They can hate the pedo, but at the end of the day, Kyle shot what was a human being. A disgusting, irredeemable, subhuman pile of trash, but he was still an American and thus by virtue has the same legal rights as everyone else. Personally, I think the pedo should've been executed when convicted and it was the justice system's failure.
That said, we can't encourage vigilante justice. The mob was ready to kill Kyle as "street justice". All they knew is this guy with a gun shot someone, so wouldn't they be justified in killing him?