"This is going to happen to all of those posting funny things on the Internet," one sign said. "You better (expletive) pay attention. I'm about to get you.""
Awful. And preceded by a story of two Mexicans being threatened with 30-year-sentences for tweeting a rumor about an attack on a school: http://articles.latimes.com/2011/sep/05/world/la-fg-mexico-tweeters-20110906