We currently use a wide range of measures to block spammers, including registration checks (bans on specific IP addresses, usernames, email addresses) as well as checks/restrictions on initial posts and so on. In the main these are very successful, blocking literally millions of spam bot registrations.

The spammers that are still getting through are almost certainly at least human-aided. There's not a lot we can do to prevent this without impacting on genuine attempts to register.

We can explore wider IP range exclusions, bans on certainly email providers and the like if the problem gets noticeably worse.