Running onto the field during a game or match is illegal. It's a serious safety issue.
It might be funny to see one streaker make security miss him like he was Devin Hester, but it's not fun to see at least four spectators in one night be able to elude the people who are supposed to be keeping everyone safe.
MORE: Must-see photos from Colombia-Chile
Security at Wednesday's Copa America match between Colombia and Chile at Chicago's Soldier Field had a very bad night, including this slip-and-slide debacle:
That was a good dozen security people the fellow ran past on a waterlogged pitch.