I kinda agree with paramiteable... it is near impossible for govt to monitor, it's pretty much the same as monitoring the streets of the world.... difference is it's the web.
Parents should drag their kids off the computer if they've been on there too long.... problems with that should be found out there and then!
I think one of the most effective ways I've heard so far of policing is kinda like what Jacob is doing(except only police should be doing this under close investigation), police posing as children online, chatting with these suspects in these chatrooms. This is quite successful in the true prevention of paedophilia.
Alcar's brought up a valid point about both children and paedophiles:
Police should be (and I'm sure they are hopefully) looking into why and how these paedophiles come to be.... people are shaped into the individuals they become with a reason. If something goes wrong along the way, we should recognise and acknowledge it, and learn to avoid it in the future.
Same with 'geek' and any other type of child who has any problem... we must acknowledge them all.
This issue cries out for people to really take notice and do something about them.