If you have a legit copy that you purchased through retail, OEM outlet, or a got it from a legit source(MS,Friend,etc.) activate it. There are mailing lists that have just as much information if not more then what you have to send to MS. I think the privacy issue is a total cop-out. What dont people want MS finding on their machine; porn, emails???? If MS really wanted to get to it, you don't think they would have already? We all have been running their O/S'es.
Maybe prices wouldnt keep going up on software if everyone purchased legit copies. You can't blame a business for protecting themselves even if it is Microsoft.
As stated already You dont have to register it..................