Cryptome is hosting several ISPs’ pricelists and guidelines for “lawful spying” activities on behalf of law enforcement. Included is Yahoo’s price-guide (hilariously, Yahoo tried to send them a copyright takedown notice to make this go away).
One of the more remarkable elements of Yahoo’s document is the sheer quantity of material that Yahoo retains for very, very long periods. From /.: “IP logs last for one year, but the original IPs used to create accounts have been kept since 1999. The contents of your Yahoo account are bought for $30 to $40 by law enforcement agencies.”