Ask HN: Is Twitter selling private email addresses?

Today I got an unsolicited email from peoplebrowsr.com asking me to look at some link they're spamming around. My twitter account is private. How did they get this address?

@handle,

To celebrate the opening of our San Francisco Command Center and the 75th Anniversary of The Advertising Research Foundation in New York we commissioned a brief cartoon history of social networking.

It's really fun! Thought you might like it.

BTW - it's trending on slideshare at the moment.

Jodee

This email was sent to realname@domain.tld. If you are no longer interested you can unsubscribe instantly.