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."
You can be asked for anything, that doesn't mean you have it. As the article you linked states, Google's privacy policy notes deleted information may live on in backups. This is common sense, otherwise they would have to touch every backup on a delete, which besides being very risky (one bug away from disaster), would mean having to go through offline tape archives of everyone's mail. If that were the case it would be prohibitively expensive to allow anyone to delete.
The question is if they have the ability/requirement to go sifting through the old backups for requested data.
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...