rogerd - 5:51 pm on Dec 5, 2005 (gmt 0)

Preventing baddies from signing up by filtering is a challenge. Blocking known bad IP addresses is good, but of limited effectiveness.

Blocking "free" emails like Yahoo or Hotmail is used by a few forums, but to my mind that's a losing battle. There are thousands of free email address domains out there, and blocking all of them is impossible. Also, many international users rely on sites like Yahoo, Hotmail, and Gmail for their primary email addresses.

If I've had spam/promotion problems from a particular domain, I've blocked signups from that domain. Sure, they can register with something else, but their email domain won't be a visible advertisement.

Doing image verification of new signups will keep most spambots out. Yes, these can be beat, but usually the financial reward isn't big enough to justify the effort.

It's a good idea to screen signups and prohibit user names that contain "moderator", "admin", etc.

If your software permits, you might find flagging certain registrations to be a good idea, e.g., those that share an IP with past problem members. They could still register, but would be flagged in some way to alert staff to keep an eye on them.

What would the purpose of the questions be, Webwork? Discourage bot registration? Or something more subtle to psych out troublemakers?