This page includes some details we've documented based on our experience with attempting to prevent SPAM registrations.

It's a living document we'll update over time.

• Acunetrix did what it promised, but we're not sure how necessary it is as we'd not experienced an attack in any of the ways it suggests are possible in about 10 years.
• Cartpauj Register Captcha did not stop SPAM registrations.
• Bad Behavior Plugin did not stop SPAM registrations.
• Stop Spammer Registrations did not stop SPAM registrations.