Any advice that says continue and move is bad advice. Shut down shop immediately and don't re-open. This is a legitimate legal firm that knows exactly what they're doing. Even if you're not in the USA, CA, UK or US territory don't think these guys don't know the laws in your Country and don't have legal firms on consignment they can toss the case to that will represent FB and still make them money.
While this might be your first rodeo for Perkins Cole this is just another day at the Office. FB didn't hire these guys to scare people and "pretend" to be Attorneys. These guys are the real deal and know exactly how to shut you down and have you prosecuted, even in another Country.