Heads up: Google does this with Gmail, too. http://news.cnet.com/2100-1047_3-6050295.html - "Judge grants subpoena and orders that all e-mail messages, including deleted ones, be divulged."
The question is if they have the ability/requirement to go sifting through the old backups for requested data.
http://gmailblog.blogspot.com/2011/02/gmail-back-soon-for-ev...