Invitation spam

We've had some problems with the invitation system being used for spam on Identi.ca. These are some proposed measures to reduce the impact of this in the future.


 * 1) Throttle invites; only N invites per M seconds (say, 25 invites per day), or X invites over the lifetime of the account.
 * 2) Invites are "earned" by activity (getting followers? Posting? Time on site?)
 * 3) Invitee can request to never receive invitations ("Do Not Invite" list)
 * 4) Invite content is passed through a spam filter (e.g. spamicity.info)
 * 5) Disallow URLs in the "personal text" section of the email