I spotted this on Twitter this morning:
RIP Trayvon Martin. Every RE-TWEET this tweet gets, counts as a petition signature for the Supreme Court to recognize his case.— R.I.P. Trayvon (@WeLoveTrayvon) March 24, 2012
This makes no sense. One of the things that makes the Trayvon Martin situation so outrageous is that that no charges have been filed against George Zimmerman. And as far as I know, Martin's family has not brought a civil suit against Zimmerman (though I'm sure they will eventually). So the Supreme Court can't recognize the case, because there is no case.
And even if there was, they still couldn't. Except in very limited circumstances which don't apply here, the Supreme Court only has appellate jurisdiction. Which is to say, until a case is ruled upon and appealed, the Supreme Court has no reason to recognize it, nor even the ability to. And even then, they would only have cause to consider it if there was some question of constitutional law at issue.
Don't get me wrong, the whole situation is appalling, and I want to see Trayvon Martin's killer brought to justice as much as anyone. But this Tweet accomplishes nothing. Less than nothing, maybe, because it makes the person who retweets it feel like they've done something useful when they've done nothing of the sort. Most social media-based activism is kind of pointless, but usually it serves some small purpose. Clicking "like" on a Facebook page about, say, opposing the Keystone Pipeline project, puts your name on a list of people could conceivably be sent to President Obama as proof that a lot of people oppose the project, which might theoretically influence his thinking. But that doesn't apply to this "petition" to the Supreme Court, for the reasons previously noted. It's the ultimate in empty activism.
(I'm assuming you already know about the Trayvon Martin story. If not, this Miami Herald article is as good an introduction as any.)