Profile spam. Got my first three today, and it was three in a row on a rapid post timestamps, which makes me suspect the process has already been automated.
Do you have a site where people can subscribe immediately and fill out their profile? Even if the profile requires an email-confirm, with yahoo/hotmail disposable accounts, that's a no-brainer, and the profile may even still be visible and be visible for Google indexing long before the new member is validated.
If you have a site like this, where you accept registrations with only an email confirm, then you have a new scourge to keep scrubbing from your site, and this just underlines what I have said before, that all publically writable space must be subjected to a spam filter. No exceptions, and no more sticking our head in the sand thinking it could never happen to me. Every bit of public write-access space on your site, every bit of data that does not eminate from your own fingers, must be filtered.
For example, consider this real-world example of a perfectly legal entry placed into the Instant Messenger field in this morning's latest spam-profile ...
Instant Messenger
Jabber:
Here are just some fun questions from <a href='http://RANDOMspamURL'>http://RANDOMspamURL</a>
about interesting things! 1. What is your favorite sexual position? explain? 2. Which do you prefer more, Recieving oral sex, or making love? 3. Do you use toys? explain? 4a. What do you do to your partner, that really turns YOU on? 4b. What does your partner do to you that really turns you on? 5. What really turns your significant other on?