On the Futility of arguing with zealous Catholics -This is a CARM post that I found interesting in this thread. I'm not sure you can view it without being a member of CARM. I wouldn't say I agree with everything, though this point is quite right:
Attack Martin Luther Technique: This can be used as a companion apologetic to the Attack Sola Scriptura technique. Always refer to your opponent as a Protestant to imply that Biblical Christianity began with the "Reformation." Always insist your opponent is a follower of Martin Luther, or one of the other Reformers,Do not accept any denials of this. Rubber-stamp him as a follower of Heresy.