That's the best idea, I think. There's always a way of inquiring about the source of the documents without getting in to advice.
That said, though, if they insist on it and they have proper ID... there's nothing preventing us from notarizing the signature. The content of the document is none of our concern and if the notarization makes it invalid, then that's hardly our fault since we're just following our duty to oblige a legal request for notarization. |