Can't invite noobs
Use-Case: trying to get free users on my account by inviting others (no matter how loser the others are)
Result: The visual overlay displays validation error upon submission.
Failed to load resource: the server responded with a status of 400 (BAD REQUEST) - https://firstname.lastname@example.org
In this use-case, I volunteer to be the loser-invite 'email@example.com'