Seeing as how there were TONS of spam accounts (since the phpBB3 CAPTCHA system was cracked), I've implemented a few changes specific to this site's forum registration.

I've blocked tons of emails, started gathering IPs to ban networks and started development of a pretty crude, but hopefully effective, antispam measure for registration.

I've purged inactive accounts (i.e. accounts that were created but not activated by the user) because they were 98% spam, but I've manually activated a bunch of accounts I know are legitimate. If you have activation problems, please email web@dl2.net and we can either manually activate it or force the activation email to be re-sent.

I went through this exact problem on a phpbb2 board about a year back. I went through manually, and cut our registered members from 900 to 390 or so, because they were all spam. It's insane! Captcha helps, but it's not perfect. I also blocked a ton of email addresses (mainly russian addresses, for the record...), and once we upgraded our forums, our spam accounts dropped significantly. We get one every now and then, but it's manageable.

There were days it'd be spam-post after spampost, a regular drive-by-spamming (I think I've gone on enough:))

So, I know what an ordeal it can be,

Thanks Vulsin!

phpBB3 is pretty intelligent in how it does not allow direct form submission - in other words, you have to fill in the form on the webpage and click "submit". I've added in an extra layer by requiring someone who is registering to click a hyperlink to activate the submit button for the terms and conditions. I've also added a couple of mandatory fields that will not allow submission without them being filled in (bots are generally not programmed for this task.)

I've hosed probably close to 200 user accounts just yetserday alone. I've banned the entire top-level domains of .ru and .pl with instructions to the (hopefully human!) registrant to mail the webmaster if their address has been blocked in error. Not surprisingly, there are a TON of registrations from Gmail accounts, but they were never activated because (in theory) the gmail accounts did not exist. I think roughly 3/4 of the deleted spam accounts were made with fake gmail accounts.

The CAPTCHA system on phpbb3 has already been broken, so it comes down to the site admins themselves. Good thing I excel at creative problem solving