Over the last little while, there has been much discussion about cooperation between telcos and ISPs, on one hand, and law enforcement, on the other hand. We've certainly seen a lot of talk about "lawful access" in Canada.
If you're curious about some of the goings on behind the scenes at American telcos and ISPs in this regard, Cryptome and Wikileaks both have some interesting leaked documentation about policies and procedures for companies like MySpace, Sprint, Yahoo! and others. Just go to Cryptome.org and WikiLeaks.org and do a little digging around.