Affiliate Marketing Secrets

If porn tube sites host large portions of copyrighted content, can a user get in trouble for downloading?
With piracy being beaten down for the last few years, and more recently, the porno industry…are these tube sites actually safe? For example, can someone affiliated with the copyright holder legally throw up a bait file as is commonly done with other protocols? I mean…usually its only at most a full scene from a movie. Does that constitute a copyright violation?