As people cast about for some explanation for the horrific shooting in Aurora, Colo., rumors have spread on Twitter and other social networks that the meme-swapping message board 9gag was somehow responsible, and that the 24-year-old suspect James Holmes had posted about his plan to shoot up a theater yesterday. They're almost certainly false.

Two screenshots have been making the rounds: One supposedly shows that yesterday a 9gag user named "9gagFTW" posted a meme-like image of a theater with text-overlay reading "TOMORROW I WILL KILL EVERYONE DURING THE NEW BATMAN PREMIERE IN COLORADO." Another supposedly shows another 9gag user celebrating after the shooting: "WE DID IT! WE GOT HIM TO ACTUALLY SHOOT IN THE THEATER!." The idea being that 9gag egged him on. This story has been picked up by at least one local Colorado newspaper. And New York Times reporter Jennifer Preston is apparently chasing the story: In a now-deleted tweet to the official 9gag account she wrote "Please call me. Urgent.... Something you need to know."

But I am 99 percent certain this is fake. Because this is an old 4chan trick. Often after a notable shooting happens, 4chan users spread fake screenshots that show the perpetrator was a 4chan user and had posted of his plans beforehand on 4chan. Recently, for example a 4chan user trolled the media by pretending to be posting from inside a home that was besieged by police. It's sort of an instant online urban legend. 9gag is basically a safe-for-work 4chan clone, where users share images and memes, and they've apparently picked up the same stupid prank.

The user 9gagFTW does exist, but hasn't posted anything about a shooting and lists their location as Peru. It was probably a prank played by him, or by someone trying to smear him. Meanwhile, someone on 4chan is pretending to be one of the shooters who got away, according to this screenshot that's being passed around. That is just as legit.

Update: Internet troll scholar (yes, they exist) Whitney Phillips has written a blog post with more background on the 9gag connection. She explains that the prank was probably launched by 4chan users, who have a long-running operation to "frame 9gag for everything terrible on the internet."

Update 2: A 9gag representative emails to confirm there was never a 9gag post before the shooting:

When we initially heard the rumor that one of our users may have been involved, we did an immediate and thorough search of the site and found absolutely zero evidence that any of the alleged posts ever appeared on 9GAG. Any reports otherwise are completely untrue and we appreciate your help in putting this incredibly insensitive hoax to rest. Our hearts go out to the victims and their families and, as the investigation continues, we will certainly help in any way we can.