Bill,
The reason why they would block the internet is quite simple really. Security in a nutshell. The internet is a nasty place, spyware, malware, and virus's are all huge concerns to company's and the govt.
I work in Information Technology specifically on the desktop side and i see this stuff every day. My company dosent have any firewell blocking at this point and if i were to give a rough estimate i would say our tech's and helpdesk folks spend about 120 man hours a week dealing with spyware and virus problems on just our site alone, our remote sites spend just as much of not more time then we do. Most of that comes from people surfing the internet going to places they shouldnt. That eats up three people's time and at somewhere around $25 to $30 per hour for a tech it adds up really quickly. That dosent even take into account lost productivity from the end user and possble data loss. All in all its a big problem.
Blocking or restricting the internet while it may stink it is an effective way to keep some of thsat stuff out of a company's computing enviorment. We did a test pilot of some internet restricting in our stores( the worst offenders) and it really was quite effective. I dont agree with it but i can see the reasoning since i deal with it firsthand.
