Officially our company has a very strict IT policy, the practice is somewhat different. However - they do react very quickly to abuse.
Recently some staff were caught distributing crude jokes and one I think pornographic images. The former were disciplined, I think the latter may now have been dismissed.
The company tolerate a certain degree of surfing, but can get quite shirty about what comes from the Inter- to the Intra-net.
Personally I find the Cat makes me more productive and I've always twiddled around doing several things at once.
Hyp