This particular idiocy just came to my attention today, via a KHOU.com Houston report from earlier this week:

Justin Carter was 18 back in February when an online video game "League of Legends" took an ugly turn on Facebook.

Jack Carter says his son Justin and a friend got into an argument with someone on Facebook about the game and the teenager wrote a comment he now regrets.

"Someone had said something to the effect of 'Oh you're insane, you're crazy, you're messed up in the head,' to which he replied 'Oh yeah, I'm real messed up in the head, I'm going to go shoot up a school full of kids and eat their still, beating hearts,' and the next two lines were lol and jk.," said Carter.

"LOL" stands for "laughing out loud," and "jk" means "just kidding," but police didn't think it was funny. Neither did a woman from Canada who saw the posting.

Justin's dad says the woman did a Google search and found his son's old address was near an elementary school and she called police.

Justin Carter was arrested the next month and has been jailed since March 27. He's charged with making a terroristic threat and is facing eight years in prison, according to his dad.