This wasn't supposed to happen and now the link doesn't work so you can't opt out or in. I can rectify that--email firstname.lastname@example.org and I will fix it.
The app sent the invitation to people who already had an account and to those who opted out.
Now I'm spending my afternoon writing apology emails; it would be funny if it wasn't so embarrassing. :(
Please forgive me. I never wanted to be one of those annoying people