Here's the MO of several pirates migrating from file lockers.
They set up scraping tubes that fetch only their uploads filled with CPA ads, popups and banners, then they upload the videos to sites that allow video embeds. These are promoted from their piracy forums.
This is most likely what you are seeing here. It's not about having the videos on XHamster , its about having the videos on their own video sites filled with embeds of their uploads from big tubes.
Xhamster.com has bursts of infringement reported to Google but it's certainly not anywhere near as consistently bad as sites like Netload.in , Rapidgator or Extabit.
http://www.google.com/transparencyre.../xhamster.com/