Is a debt validation request a good idea for an outstanding credit card bill?

I just got a letter from a lawyer Creditor's Rights firm notifying me of their intention to collect on an outstanding credit card bill. These guys, because of their reputation in my state (and elsewhere), scare the heck out of me- they take people to court left and right. I do owe the money, but am jobless and have no asset at this time. I have read this is something a debtor should absolutely do to verify the collector is legally and rightfully able to collect on the debt, but I do not want to annoy this law firm as I am hoping to negotiate with them and avoid a court case.