Our forums were inundated with a huge pile of Chinese spam yesterday evening. I've banned the user, and unpublished all of their content...but, folks receiving notifications from the affected forums would have gotten them via email. Sorry about that.
We have a pretty big list of spam prevention measures here at Virtualmin.com, including CAPTCHA, email verification for new users, and several honeypot hidden fields (so a bot would have a hard time making it through the registration process without tripping up at least one of those mechanisms). It was all posted by an actual human user who manually entered all the data, as far as we can tell.
I'm currently researching what our other options are; we have used both Mollom and Akismet in the past, but they were blocking legitimate messages far too often (like 20% of all posts were being blocked as spam), making users angry and confused, so we disabled them. We may re-enable one or both of them to see if the false positive rates have improved in the past couple of years.
Thanks for your patience while we murder the spammers...err, rather...clean up their mess, and try to figure out ways to stop them in the future.