Twitter and identity

I just signed up for my twitter account.  I discovered in the process that someone had already signed up using my email address. One password-reset later, and the account is mine.  I don't remember getting any sort of alert in my email that I had a twitter account.  Maybe there was and I overlooked it, but it is a nice reminder that digital identities and brands are easily stolen.  The person using my account only had one follower.  I wonder what she will think when she starts getting library-related tweets.