DS1 been looking at porn .... how do I block it

[littlemissbossy]

Now I know it's probably normal teenage curiosity but I've got two younger children who use the same computer - so I need to know how to block it - do I just contact my internet provider??

Netnanny?

I don't think internet providers will block it although I may be wrong

do you use an internet service provider which offers it as a service eg I use Telewest and I think it has parental control ?

I have tesco internet security and you can set that to bar porn type things .
The gambling block is very picky though so not sure if the porn on would ban things like discussions on here that mention sex.