People had gotten really comfortable standing behind the Jaguars' end zone. It was a safe space, unbothered by people crashing through after touchdowns.
They're still safe -- the Jaguars are down 17-6 to the Chargers, a game you might suspect doesn't involve touchdowns for Jacksonville -- but after Justin Blackmon did this to an unsuspecting guy, they might want to think twice.
I like that Blackmon lowers his shoulder and kinda stares him down after the hit before moving on to things he finds more interesting. Judging from Mr. S.A.F.E.'s immediate ability to gather his hat and give Blackmon a pat on the shoulder, he's okay, and therefore we can laugh at him.