Also if one feels it acceptable to do so, he could forge the contact information. This would be against the TOS I imagine, but I think many services would be happy just to get the $$. It's not like this is a bank account which requires social security # and other verification.
Again, I don't condone illegal activity and use this knowledge for good!
You don't necessarily need to forge any contact information to remain anonymous. Use an anonymous mail drop. Several places in different parts of the world offer these and they will basically either forward mail to you via post or wills can it in where you can check it that way. The ones that scan it in are really nice and convenient because you have your mail anywhere you are. One that immediately comes to mind is www.earthclassmail.com
As for a phone number, use Tor to browse over to www.k7.net
and set up a free voicemail/fax account.
This way, you're not breaking the ToS as you are supplying valid (though anonymous) contact information.