Legitimate debt collectors have access to current addresses so that they can notify by mail before they start calling you. Most debt collectors will not request a social security number from you because of privacy laws. The exception to this is collection for back taxes, child support, and court ordered judgments. These types of collections are performed internally and do not outsource. If the man got upset chances are he's frustrated at not getting the information he wants. Despite threats to the contrary, we do not have debtors prison.
As for old info, anyone can pull up outdated info on the internet through a simple search of a name. Also, for a few dollars per person basic address and phone number information can be obtained through People Search. Most real collection agencies use Lexus Nexis and pay the steep charges required for access. Lexis Nexis provides all information current back to birth on a person.
I'm still betting he's a scam.