Biggest email data base ever

Guess who?
That's right Gmail!!!
I read on Googlemania that they'd given away around 50.000 GMail invitations in a month (that's only Googlemania).
What does that mean? think about it, for every GMail account you get, Google gets two ways to get to you, your brand new GMail account and the one they sent the invitation to.
Could you imagine the damage that can be done with such amount of information? What if that data base gets to the wrong hands?