OP I think you should keep close attention to [CLUB] The SpamBusters Club thread because from two years with a lot of success they are investigating all sorts of abuse, especially bumping and other forms of spam.

There are constantly new ANN threads taking under the microscope and of course, many of them are obviously breaking the rules using alt accounts or bumping services.

I think it could be a good source of information to make this list of "ANN threads that are using bumping services" even more accurate.