If you wanted to make the declarative statement "Last Wednesday's internet SOPA / PIPA protests killed SOPA & PIPA," there exists some pretty strong evidence to back you up.
First, Congressional support for the legislation took a nosedive following the protests. And it doesn't appear that Wednesday's protests simply happened at the right time - an emphasis on a foregone conclusion. You can actually see a seismic shift in support and opposition to the two bills, and the clear line of demarcation was Wednesday's blackouts.
Then, Senate Majority Leader Harry Reid delayed action on PIPA "in light of recent events." On the same day, SOPA author Lamar Smith released a statement saying that he would not move on SOPA until there is "wider agreement on a solution."
Of course, the DOJ's takedown of MegaUpload the very following day took a little steam out of the successes of the protest. And there is plenty of other harmful legislation out there that threatens internet freedom and privacy. But there is no denying that for one day, the internet community did affect policy.
And one of the major ways that they did that was through social media - especially Twitter. #SOPA #PIPA and #Blackout hashtags reigned supreme through the whole day. People were buzzing about the protests. And Vimeo user Andrei Taraschuk has created a couple of cool visualizations showing how American Twitter users discussed SOPA on that day.
Here's a video of Tweets from 8am to 8pm on January 18th containing the #PIPA, #SOPA, or #Blackout hashtags. Tweets are displayed in one-minute interval:
And here's a video of tweets specifically about the Wikipedia blackout. As you might recall, Twitter kind of had a collective freakout about the perceived inaccessibility of the site:
Twitter announced that there were over 2.4 million SOPA-related tweets floating around the Twitterverse from 12am to 4pm on the 18th.