Do you know what the common key was between these services? I bet it was email.
That's why I sign up for services with a custom email address, that is linkedin@domainname for linkedin, meetup@domainname for meetup, etc.
That's why I sign up for services with a custom email address, that is linkedin@domainname for linkedin, meetup@domainname for meetup, etc.
I guess using random@domainname may work better?