Facebook, privacy and perverts

The Sun leads on calls for Facebook to be held responsible for perverts using false identities on the site.
But how can they do it?
Is it practical?
There's some useful information from the Internet Watch Foundation, here at 10 Privacy Settings Every Facebook User Should Know and at the Child Exploitation and Online Protection Centre but parental responsibility is the key.
It can't be left to other agencies while the technology is not up to policing the web. The risk is just too great.
The internet is a force for good but it has allowed individuals with latent perverse desires to come to the fore.
We must all be on our guard.