That didn’t take long. The clean-up crews are still sopping up slicks of crude in the Gulf of Mexico and investors are dumping shares in the culprit, BP. Meanwhile, on land conscientious members of the public are heading to the biggest public forum, Facebook, to mobilize a boycott against BP.

Last month’s still-uncapped oil spill off the coast of Louisiana has environmentalists, shareholders and politicians in an uproar. But what is Joe Consumer doing about it? A good number are joining the Boycott BP Facebook page to vent their activist rage. Nearly 6,500 people have joined the cause, and it is gaining about a thousand new members per day, some of whom are posting details about how best to boycott the oil giant. It’s also become a forum for addressing past wrongs, as one Chicago-based group member says:

Check out other BP problems like there Naperville, IL site and refinery that dumps into Lake Michigan in Indiana. I have been boycotting BP for at least 5 years and will never stop, its sad something this bad had to happen to get everyones attention.

But as The Big Money article notes, a few thousand Facebook members isn’t exactly a “Million Man March.” Plus, in the states affected most by the spill, like Louisiana, a boycott BP effort could be tough seeing as there are no BP gas stations in the state. If anything, the company will get hit on Wall Street, as is already happening, not so much at the pump.

But let’s consider something that’s not a multi-billion dollar oil company with guaranteed consumer demand. Say, Arizona’s new unpopular anti-immigration law. There has already been strong social media response to the law. Left-leaning bloggers are outraged, even publishing instructions of how to boycott the state. The Facebook page Boycott Arizona 2010 already has 12,800 members and is growing fast. There was even a boycott protest event organized through Facebook for the Arizona Diamondbacks game against the Chicago Cubs at Wrigley Field in Chicago.

But it’s unclear if this sort of Facebook organized protest will be effective. Is 12,800 angry souls enough to force a legislative about-face? Not likely. Plus, just because you join the boycott page on Facebook does it really mean you going to stop sneaking Arizona exports. “Can you live without Sky Mall, P.F. Chang’s, domain-name registration and internet pornography?,” Gawker asks.

From what we’ve seen of the hundreds of protests and boycotts organized on Facebook, the organizers are good at drawing attention for their cause, but the effect on Main Street is rarely seen. Like some businesses, they fail to capitalize on the power of social media to mobilize the masses. What these grassroots Facebook boycotts seem to lack is a centralized leader or organization to get people inspired. It will be interesting to see if the recent organized boycott by the National Council of La Raza, the largest Hispanic organization in the U.S., will have an impact (and a Facebook page) on the Arizona economy, and whether scattered Facebookers will impact BP’s bottom line.

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