I guess you could say that they are only covering their own backs. There is little that an ISP can do to stop illegal Kazaa, IRC, downloads, etc. But they CAN remove known illegal content news servers.

"Being an ISP is not the easiest job at the moment. Many ISPs are forced to police their users and make sure they do not violate copyright laws, and respond to inquiries of content owners. Besides that they have to survive in a difficult market and keep their customers.

NTL a large provider in the United Kingdom has decided to drop several alt.binaries from its news servers. These news groups are used to post (illegal) software, movies and music and a place where a lot of pirates meet."

More here

My ISP did a pretty good job of all that stuff - it blocks all ports except 4 that I know of - HTTP, FTP, 7000 and 14000. Every single one. Can't DCC on IRC, no multiplayer games, no KaZaA/P2P, no nothing. It also filters out pr0n and warez sites as well.

Hmm... that sounds like your internet freedom being crippled, I'd be leaving that ISP of yours (if I were you).

I don't have a choice. The ISP is the school district that my mom works at, and it's free - no chance of us switching. I've been bugging for a DSL, but my mom doesn't seem to realize that the DSL I would choose, which is 768 down and 128 up, is effectively 27x faster than what we have now