I do not know of any studies, but there are many people who know that not all pedophiles have offended... yet. But they believe that pedophiles are a threat to children and will offend eventually.

If you shouted that out in a crowded street, I'd assume you were joking. Probably something to do with friends, such as a dare. I don't assume people with a pedobear sticker on their car or shirts are actually pedophiles. Between that, the bystandard effect, people being cowards, and people who disagree with use of violence for such it seems unlikely anything would happen.

You could look at the treatment of people like Jack McClellan. (just noticed I have not heard anything about his appearance in some episode about the canadian border.