Even services such as StopForumSpam are now queried by bots to see if they match any data and change as required to bypass these systems.
And ultimately, a manual spammer registration can nearly always bypass any system in place.
However, in the near future, we hope to release a new XenForo only**, Anti-Spam service which should provide an additional layer of security against the spam bots, even manual registrations.
Whilst the exact details on how the service works will be kept under wraps for the moment, it is already being trialed on several sites and generating very positive results.
The system is also cumulative as you would expect, meaning the more people who use the system, the more effective it becomes. As such, it will also be provided with an easy to use snippet of code which addon developpers can include in their own Anti-Spam addons to link in with the service.
Hopefully, our unique ways of detecting and preventing the bots from registering will give all XenForo forum owners a robust security net against spammers of all types.
Stay tuned for more information
** We may expand the service to cover non-xenforo boards in the future.