I’ve just come across backlinkengines.com after following a twitter link
Not nice. Not nice at all
I’ve only just come across this, but for anyone using the forum module, keep an eye out, and think about upping things like mderatio and whether users can post links in their signatures.
It looks like it may well be capable of getting round capcha also.
I’ve seen other tools like this successfully targetting phpBB already.
[Mod Edit: Moved to the General forum]