Need way to keep Teenager off Facebook, but still use CPU for Homework

[pinion]

graylocks wrote:
[quote=pinion]
I have to throw my vote in for opendns, I have mine configured at the router.

yes but do realize that anyone with admin privileges can change the DNS servers on a computer and that will bypass the OpenDNS ones set at the router level. it's how mom could visit Facebook on her computer while sonny boy couldn't on his.
Why would you give a child admin privileges?