I don't know if you gals have ever heard of this site verifyhim.com but if you haven't joined yet, you are missing out on a great resource. Basically it's a black list for not just dangerous clients but ass holes and time wasters too. There search database returns all sorts of useful info on the guy you want to find out more about.
There's also a wealth of helpful tips and tricks to help keep you smart and safe.
It's a great networking tool as well as a beautiful support system of other lovely ladies who can relate to all the same things from working in this business.