Whether or not they are scammers is a matter of opinion. They are an asset recovery company called Legal Claimant Services, and they do have a verifiable record of recovering lost or abandoned stocks, bank accounts, and the like. In my book, they are scammers anyway, because their finder's fee is 30% of the recovered amount, and because of their high-pressure, never-ending sales pitch. Reputable companies in this business generally charge 5% to 15%, depending on the size of the stash.
See the complaints under # 646-770-9250. They seem to have opened a new "branch" today. And they do have a website:
http://www.legalclaimantservices.com/