We certainly noticed an unusual high volume of SPAM attempts yesterday, most of which were automatically stopped, but with a few managing to create accounts and sending a number of private (Conversation) Messages to some of our users. I believe we have removed these shortly after they were reported yesterday, and quickly applied a number of measures to completely block the source, email patterns and the content promoted.
We have also disabled the Conversation content preview inside emails notifications - for users that have this option enabled. This means that for private messages, the Email notification will no longer show a preview of the content and instead require to log into the forum to see it. This gives us some time to block or clean up the content, even by the time the users see the notification.
Your timely reporting is very much appreciated as it is a very effective tool on open platforms such as ours - and which along with our arsenal of security mechanisms help tremendously in keeping the forum clean and our users safe. We cherish and celebrate this amazing community, its content and friendly atmosphere, and are fully committed to keep it this way - both with your help and the help of our remarkable moderators.
Interesting enough, one of the comments in this very thread came from such an account - which tells me this may not have been just a random bot attack, but instead something potentially more orchestrated, with real humans involved, which makes it much more difficult to detect and explains why some managed to get through. There were a good number of source IPs involved as well, which again shows a more elaborate effort. That said, together with the changes we already made, we will continue to keep a vigilant eye going forward and encourage you to continue reporting any unusual activity or inappropriate content in order to daunt these efforts in the future.