Yes, I think that restricting web access at school and some workplaces is probably a very good thing. What is bad is that it is usually done by people who don't know very much about the web or about the blocking technology, and it is often done by management folks who refuse to take responsibility for their own actions.
There are other work environments where blocking any traffic is a very bad thing. I work at a government facility where pornographic sites are blocked. To my mind, it would be much more effective just to fire people who spend their workday looking at p*rn on the internet; in this case network blocking results in employees being retained who would be better off gone. --scott
"C'est un Nagra. C'est suisse, et tres, tres precis."