To understand why some protesters are breaking the windows of corporate shuttles in Oakland, it helps to take several steps back from the fray of the immediate situation. The political quagmire in Bay Area cities that is producing such demonstrations has ties to larger regional and national trends, and a long local history.
Let's start with the national situation. As a result of both the structural economic turn towards neoliberalism that began in the seventies, and the more recent Great Recession, "the rest of the country is dying," as Michael O. Church puts it. Automation and outsourcing have hollowed out major sectors and regions of the American economy, producing phenomena such as the Rust Belt. As a consequence, many Americans are migrating across the country to regions where jobs can be found in order to better their economic prospects. The San Francisco Bay Area is one such region (the fracking fields of the Dakotas are another).
Another national trend is that Americans are starting to prefer urban living to suburban living (I won't get into why this is -- it's a complicated and interesting subject in and of itself, but less important to the present topic; let's just accept it as a given).
The Bay Area economy has several idiosyncrasies that I should note. One is that "tech"  -- a vague term which can mean the computer software / hardware industry, biotechnology, venture capital funding, etc. -- is a large part of it. Consumer technology names like Google, Facebook, Yahoo and Apple get thrown around a lot, but there are plenty of lesser known ones, both because the Bay Area is a haven for small technology firms that fly under the radar because of size, and corporate-facing ones (e.g. Salesforce, Cisco) whose products one doesn't consciously interact with on a day-to-day basis.
Technology companies tend to employ higher-than-average-income workers, notably engineers (and notably software engineers). But in fact engineers tend to be a minority in tech companies -- except for the smallest, newest ones -- since most of the headcount is accounted for by human resources, public relations, sales, marketing, legal, executives, etc. It just so happens that software engineers are in high demand right now as a profession in the Bay Area, so this job type has an additional incentive to migrate the the Bay Area. Technology companies also employ H1-B (foreign) workers as a significant part of the workforce, so the migration to the Bay Area is happening internationally, as well.
Over the years, the Bay Area, and especially San Francisco, has acquired a reputation as a boom town. The Gold Rush and the first Dot Com Bubble were two notable examples of economic booms. Today the cycle is starting up again, with what we now call "entrepreneurs" seeking their fortunes streaming into the area (but as has been true historically for booms, the financial rewards of the boom accrue to very few -- most 49ers didn't get rich off gold; most software engineers aren't Mark Zuckerberg). To sum up, many people are migrating to the Bay Area to work, and engineers (especially software) are a visible part of that group.
A longstanding problem in the Bay Area is transportation, specifically the lack of adequate public transportation. The existing system lacks integration -- each county tends to have its own independent services, generally -- and coverage is patchy in lots of areas. The result is that to have a tolerable commute, many Bay Area employees resort to automobile, clogging the main roadway arteries.
Historically, tech companies located themselves south of San Francisco in what came to be known as Silicon Valley (which is not actually a geographic valley; mostly the term refers to the San Francisco Peninsula south of San Francisco and the area around and including San Jose). Now, some have satellite offices in San Francisco. Newer tech companies, like their employees, tend to prefer being in San Francisco, largely for access to talent (but also because of tax breaks meant to attract these companies to the city -- Twitter is an (in)famous example).
|Map of San Francisco Bay Area|
Enter the "Googlebus." For corporate employees living in San Francisco (and now Oakland as well), various companies, including Google, started to provide wifi-enabled double-decker corporate shuttles down to their main headquarters on the Peninsula. For the companies, this solved three main problems: getting their employees to the corporate campuses in a reasonable amount of time, allowing the companies to employ people who lived in relatively distant cities and allowing the employees to work while commuting.
However, many in the Bay Area are not as happy about the corporate shuttle development, seeing it as an example of class stratification: "Googlebus" for the relatively well-off corporate employees, and subpar public transit for everyone else. This sense is compounded by the fact that these behemoth busses cause inconvenience for other commuters by idling in (particularly) San Francisco streets waiting for the workers to file in, sometimes even at SF Muni bus stops. (The city of SF is looking into fining the corporations for this practice.)
This pattern of economic and social bifurcation is familiar in American life in the past few decades, especially accelerating since the Great Recession. Recall the slogans of Occupy: "We are the 99%!" and "Banks got bailed out; we got sold out!" Many can only find work in temporary, low-paying and part-time jobs, if at all. The austerity policies that are gutting social services, while a small elite's fortunes continue to rocket upwards, have not spared the Bay Area. To just take one social services vertical, public education: San Francisco City College is in danger of losing its accreditation and tuition at state universities continue to rise in real terms. Many see the "Googlebus" phenomenon as another instance of this bifurcation.
The other main issue besides transportation the protesters said motivated them was "gentrification."  By this, they mean the rise in housing rents which lead to displacement of long-time residents, and the resultant transformation of neighborhoods which often takes place along class and racial lines. Since real estate prices have risen so dramatically in the Bay Area recently as a result of high demand and low supply, incentives for property owners to remove lower-paying tenants in favor of higher-paying ones has increased in tandem. The notorious Ellis Act and other legal chicaneries are often used as the pretext to kick people out of their residences. The direction of relatively poorer residents is moving, generally speaking, from San Francisco to Oakland and from Oakland out into the suburbs (and of course there are migration patterns within the cities, depending upon the perceived attractiveness of various neighborhoods).
There have been four (by my count) corporate shuttle blockades thus far. Two in San Francisco (December 9th and December 20th) and two in Oakland (both on December 20th). In each, a relatively small group of protesters surrounded a bus until the police came, and then everybody went on their way. There is a different group of people protesting in each city. The San Francisco group seems to be drawn from the NGO / professional activist crowd whereas the Oakland group appears to be frequenters of the Occupy Oakland / anarchist  protest scene. The Oakland protesters were more aggressive, breaking a shuttle window on one occasion and handing out hostile flyers.
The anger shown towards tech employees by the Oakland protesters (and certainly, this sentiment pervades beyond their clique) is a bit perplexing. After all, managers, lawyers and nurses, for instance, earn more in San Francisco than app developers. Nurses are more numerous. And there are no comparable protests against them. In addition, the kinds of people who are aghast at the high salaries of tech workers were not too long ago defending the (sometimes) comparable salaries, perks and benefits of union members during the recent BART strikes. In any event, making a grievance out of the fact that another worker earns more or has better perks than another seems to be a race-to-the-bottom type strategy, typical of oppressive management, not leftist agitators.
Furthermore, the workers at, say, Google are not (if I may use Marxian terms) the bourgeoisie -- they're proletarians (albeit with better job conditions than was historically the case), and have many work-related grievances of their own. Many work excruciatingly long hours, can be recalled to work at any time -- even the middle of the night (being "on call") and face discrimination at the workplace (there has been a cottage industry recently in journalism of highlighting sexism, racism, ageism, etc. in Silicon Valley). Perhaps most ominously, capitalists, enraged by the high salaries that the engineer labor shortage mandates, are actively working to undercut salaries by means of, among other mechanisms, collusion, H1-B workers (who, because of their precarious legal status, are particularly vulnerable to management pressure), outsourcing, and expanding the domestic pool of labor (I suspect this is the motivating force behind the recent spike in interest in getting women to code -- not that gender egalitarianism shouldn't be a goal in its own right, of course).
I want to make clear that I support these protests, and think the tactic of blocking corporate shuttles is an entirely appropriate one to draw attention to inequalities in local life.  My gripe is that these issues are a lot bigger than Google employees, Google, or even "tech" (whatever that is). They are issues that have their root in capitalism, fundamentally, and "tech" is just the way that these processes manifest themselves in the Bay Area. Like-minded protesters in Detroit might, hypothetically, protest Big Auto, but they'd still be grasping a part of the same capitalist elephant. Populist opportunism that looks for a convenient scapegoat like tech workers might seem like an attractive way to proceed, but it is ultimately a bad politics because it is intellectually incoherent.
Another question is: why are these protests happening now? My theory is that we are currently at the point where the literary class -- that is, journalists, artists, activists, writers, editors, etc. -- are getting priced out of their current living situations. Rebecca Solnit wrote her first "Googlebus"-bashing article (which I suppose could be considered the vanguard article of this genre), not coincidentally, with her recent experience of entering the San Francisco housing market in mind. Many on this income level (lower than your average engineer, higher than your average janitor) despair that the cities they lived in for so long at relatively low prices (see the aforementioned fact that there is a new influx into cities, generally, and Bay Area cities in particular) no longer resemble the bohemian landscape they once knew -- especially when that landscape includes them. They do, however, have access to the media, as well the ear of others willing and capable of street action.
What the larger public thinks about these dynamics is hard to discern (and is often drowned out by buffoonery, extremism and posturing on all sides... nothing new in Bay Area politics! ) but the University of San Francisco did conduct a recent study of San Franciscans' attitudes about tech and inequality. Speaking in broad terms, citizens generally looked favorably on "tech's" contribution to the city and its economy (especially compared to the dismal national conditions -- my interpretation), but noted that inequality, especially in housing, was a concern.
In any event, valuable data about labor, urbanism, transportation and economics in the Bay Area that would shed light on this problem is very hard to come by. Where do "tech" employees live? What are their transportation patterns -- bikes, busses, trains? How long have they been in the Bay Area, on average? Are they migrating internally within the Bay Area? If so, how? What are their demographics? What about other types of workers? Etc. Having the answers to these questions would complicate if not challenge the simplistic narrative of "White, male tech workers from outside who don't value our culture are coming into the Bay Area and displacing the long-time, minority, poor community members!" that seems to be so pervasive in some people's minds. These answers may be available, but, so far as I have seen, they mostly haven't been surfacing in the local journalism. This is partly the fault of journalism which (no surprise here) is poorly covering the issues (there are exceptions, of course). It is also an issue of the declining resources going to journalism, so there is less research to go around.
What journalists have been covering are the more superficial aspects of gentrification and inequality -- the tropes of "tech workers behaving badly" and its righteous inverse ("Don't. Be. Fucking. Douchebags!"). But what the Bay Area is dealing with are primarily issues of class conflict, not issues of manners. Even if every "tech bro" comported themselves with impeccable modesty and grace while riding the "Googlebus," they would still be riding the "Googlebus."
Part of what makes the Bay Area's political situation so hairy is that there is no one overriding issue eclipsing all others in importance. "Gentrification"; income inequality; public transportation; urban planning; evictions; privatization of public space; non-payment of corporate taxes ... all are interrelated components of the predicament. It's difficult to know where to start, or even how to talk about "the problem."
To add to the difficulty, there are significant numbers of people who aren't the Evil Capitalists of leftist lore who benefit from the aforementioned dynamics. To give one example, rising real estate prices increase the value of homes, increasing the wealth of homeowners. In this way, there is a direct economic antagonism between renters and homeowners. Organizing a struggle against, say, real estate developers is one thing. Organizing a struggle against real estate developers and owners of a third of San Francisco residential real estate and their families is another thing entirely.
One could propose plenty of solutions; here are some offhand. Get a decent, integrated public transportation system. Repeal the Ellis Act (and Prop 13, while we're at it). Tax the rich... or just collect the taxes that they and corporations have been evading. Expand housing supply in the cities, and make it denser. Get stronger rent control laws. Expand public housing. Develop other areas in the Bay Area besides the cities. Develop other areas nationally and internationally (although, of course, these would be outside of the Bay Area's control). One word: regionalism -- eliminate the parochial interests that divide cities and counties and start planning with the whole Bay Area in mind. Hey, we didn't even have to overthrow capitalism! See how easy that was?
But, of course, implementing these measures is not as easy as snapping ones fingers. And given the post-Occupy activist zeitgeist of not proposing any positive program, and existing reformist forces' inability to implement almost any political change, and the strength of capitalist forces moving us in precisely the opposite direction, I'm not optimistic that these issues will be resolved satisfactorily anytime soon.
The future of the bus-blockading tactic will probably be limited to its current manifestations: very motivated small groups of activists making symbolic, temporary stops of a limited number of corporate shuttles. This is because the actions can't be publicly organized, and it is a pretty large request to ask a non-mobilized individual to start organizing in a bus-blockading clique -- it's not like a rally that one can stumble into where one has the anonymity and protection of being in a large crowd of likeminded people. Generally, one can only use a tactic for so long before it fails to inspire people or the establishment figures out how to defeat it, but I don't think we're at that point quite yet.
There is a possibility that the groups already protesting could escalate the intensity of their tactics, moving more into vandalism and sabotage, or even commandeering the busses. Such an intensification would raise the question of what the establishment response and popular response (or backlash) might be. There is also the space for other symbolic actions against the corporate shuttles. 
In conclusion, partly as a result of its own historical screwups, and partially because of a national economic situation that is beyond its control, the Bay Area is in the midst of a difficult political situation regarding housing, transportation, labor, urban planning and income disparity. Some resistance is emerging, but it is largely at the margins, even though its drama occasionally grabs headlines. Solutions are easy to imagine but politically hard to implement, mostly because economic power is in the driver's seat.
 One never quite knows what is being referred to by "tech." It could be large software corporations in the Bay Area; large software corporations in San Francisco; large corporations in San Francisco; large new corporations in San Francisco; biotechnology firms in the San Francisco Bay Area; the entrepreneurial startup scene; the network of venture capital funding; etc. etc. etc. One of the difficulties in talking about it is that it can refer to so many things. Walmart has sophisticated supply chain management technology -- is it "tech"? What about Papa John's -- it has a website? Or Microsoft and Amazon, even though they're not in the immediate Bay Area (but do have satellite offices here)? Or distant firms that Bay Area residents telecommute to?
 When "gentrification" is invoked by a left-leaning individual, it is almost certainly in the pejorative. There is a common method of argumentation against "gentrification," however, that is problematic. Specifically, when a person of income (or privilege or whatever) X moves into a neighborhood and then immediately declares that she is against "gentrification," particularly for people of incomes higher than X. The hypocrisy therein -- that she was part of the "gentrification" process not long ago -- seems to escape only the people making these kinds of arguments. The point is nobody has an overriding moral claim to land in the Bay Area; everyone was part of the chain of "gentrification" at one point or another (notwithstanding Native Americans).
Other arguments against "gentrification" focus on cultural forces that are being created or destroyed or are changing, but these are very subjective, fetishize a mythical and timeless notion of a location's essence, and are, in my mind, unconvincing. Moreover, it is undeniable that "gentrification" brings some positive benefits -- the issue is just that those benefits are distributed unequally. None of this is to suggest, however, that people should be extracted against their will from their homes either by legal or economic circumstances, which is what I understand to be the main problem with "gentrification."
To sum up, arguments against "gentrification" often misstate the problems with it. We should probably use a new term that ditches the argumentative baggage associated with "gentrification" to describe the perceived negative changes that occur in a location when real estate prices rise.
 Anytime one talks about protests in the East Bay identified by most media as "anarchist," one also needs to recognize that "anarchist" is an imprecise label that doesn't describe the political philosophy of all the participants of the protest.
 Just to elaborate on why I support the protests: to be a successful action, an action must satisfy two requirements -- it must be well-targeted, and it must be educational. I think the bus blockades satisfy both conditions, as the "Googlebus" is a symbol of class inequality whose blockage only hurts the pockets of the large corporations, if at all. And the flyers, while I, as I state, disagree with some of the content, were generally on point regarding class stratification in the Bay Area. One doesn't have to endorse every last word of every flyer that is handed out at an action to endorse it (an impossible standard that would result in not being able to support any protest). Also, one can't fault these actions for lack of effectiveness, given the limited resources of the protesters. As is often the case, these protests are largely symbolic -- asking them to singlehandedly bring down Google, for instance, would be entirely unreasonable.
 I think my favorite loopy ideology came from a protester who advocated something similar to Mitt Romney's self-deportation strategy for undocumented immigrants at this earlier protest, notable for its smashing of a "Googlebus" piñata. Her words were, approximately, "GentriFUCKation! There's not enough space for both the real residents of San Francisco and the outsiders! If you're from Wisconsin, or Ohio, or Indiana, maybe you need to leave and go home to where you came from!" But, rest assured, there are plenty of other contenders for the loopiest ideology crown.
 Symbolic action could potentially include:
- The announcement of a "free ride on the Googlebus day" where anyone is encouraged to board the corporate shuttles and to go to the corporate campuses, or perhaps to demand they operate as Muni busses since they are Muni stops; entertaining street theater ensues
- Renting a corporate shuttle and masquerading as a "Googlebus," bringing the corporate employees to an entirely different location, or perhaps brining them to the corporate campuses, while playing an informative video about corporate malfeasance / the economic situation the entire way
- Distributing pamphlets, etc. to corporate employees while they are stationary, queued for their shuttle (employees are likely under instructions from corporate PR to not interact with any protesters)
- Turning the "Googlebus" into a giant banner rolling down the highway by spray-painting some slogan on the side