This is legal because like most contracts you sign with service providers they read, "And subject to change at any time for any reason" or "We reserve the right

This is legal because like most contracts you sign with service providers they read, "And subject to change at any time for any reason" or "We reserve the right to modify this contract at will". Increasingly, this will be built into new contracts. There are a lot of third party contracts signed in business where one party will take a particular action based on the needs/wants of a third party. Again, only if the ISP is notified does this come into effect. Download all the Ubuntu iso files you want via P2P you want and you'll be uneffected.