Like most scams it is designed to play on your fears and get you to pay money you do not have to spend. You may, at anytime get a copy of your Grant deed from a title company or the county for a very modest fee. Most everyone already has a copy of this in their final closing package from the Escrow/Title company.
Be careful of these bogus resellers of public information. If you receive any document, that pertains to your property, and are unsure what it means please check with a trusted local expert such as your Realtor, an attorney or your tax professional.