BBC:

Georgia death row inmate Troy Davis was executed amid a massive outcry by Twitter users, who documented every minute of his final hours. Will social media change the way people view the death penalty, or will the Davis case change the way social media users view politics?
On the night Troy Davis was executed for the death of officer Mark MacPhail, thousands of outraged Americans flocked to social media to register their disgust.
Celebrities like Martha Plimpton and Alec Baldwin tweeted about the case, and Outkast artist Big Boi posted photos from outside the jail to his TwitPic account.
“Troy Davis”, “Letter to Georgia” and NO EVIDENCE were all trending topics in the US throughout the night.
But all the angry tweets and online petitions did nothing to prevent Davis being executed at 23:08 local time in an Atlanta, Georgia prison.

But Alec Baldwin sent a tweet! What more can you expect of any mortal man?