ProQuo describes itself as a service that allows users to
Stop Junk Mail and Protect Against Identity Theft for Free
I signed up and played around a bit some time ago. And then forgot about it as the service wasn't available to Canadians.
I was reminded of ProQuo yesterday. I received 2 (yes 2, deux, zwei, etc) 'newsletters' from them, thanking me for signing up.
Looking at ProQuo's registration page, it is indeed opt-in for getting the newsletter so my bad - I must have been feeling tired. I definitely didn't opt-in twice though.