The rise of "Tube" porn sites, such as YouPorn and RedTube, are making massive waves in the world of online pornography.

To begin with, according to the UK regulator Authority For Television On Demand, porn is becoming harder to control because of them. Such sites, which feature free movies and extensive clips, don't put up barriers to hardcore pornographic content as is the law in the UK. And ATVOD cannot act on sites outside the UK.

In addition, the Tube sites are changing the face of the porn industry itself. Speaking to the BBC, porn producer and spokesperson for the Adult Industry Trade Association, Tom Dennis, claimed that it was hard to justify spending significant amounts of money on making porn films because there was little return.

"Less work comes around because people aren't supporting the porn industry," he said, referring both to sites such as YouPorn and pirated content.

"They'd rather watch their porn for free then pay for it."

However, that doesn't mean that the industry will disappear entirely. The interest in live nude webcam shows is rising dramatically, both in the watching and making of.

"It's live and cannot be pirated," Dennis told the BBC.

"I think it's going to take over, to be fair, the web-camming side of stuff."

Pic: Barcelona Sex Project by Erika Lust Films