Originally Posted by KrisKross

All the video sharing sites I've seen that are geared to porn request a 2257 link but it's not mandatory.

Legally, it's hard to say whether or not the site can get in trouble. From what I understand, there are previsions in 2257 that essentially exempt certain sites from 2257 requirements if they have no reasonable control over their content. For example, this is why Google Images doesn't require 2257 statements.