“I am convinced the feds (NSA, DoHS) are already covertly identifying firearm owners and keeping the records hidden despite U.S. law forbidding such record keeping.”
In some (maybe most) of the time there is a record of you buying a firearm, but that doesn’t equate to you owning one.
Feral law requires that FFL holders, i.e., gun dealers, must keep all of the BATFE Form 4473s on the premises of their businesses. LEOs can look at these records anytime, just not remove them from the premises. When a business closes shop, BATFE takes possession of the forms. So they already have a database of the closed shops. How hard would it be for a LEO to take his cell phone into an existing business and snap photos of those forms and compile them into a database?
Think of all the other ways the ferals can identify private gun owners - (1) if you pay for a gun/ammo transaction with a credit card, you can be traced, (2) the U.S. Postal Service can scan the mailing labels of all those NRA and other gun/hunting magazines, (3) if you possess a pistol license or hunting license, you are already in a state database, (4) if you buy a feral duck hunting stamp you are already in a feral database, (5) under ObamaCare, physicians will become more intrusive into your private life and ask you whether you have guns at home - this info will find its way into a feral database, (6) Congress can at anytime repeal the Tiahrt Amendment and the DoJ/BATFE's firearms tracing database could become public knowledge to the newspapers, (7) the 1986 Firearm Owners Protection Act, which prohibits the registration of firearms records, can be repealed by Congress, and finally,(8) the National Instant Criminal Background Check mandated by the Brady Handgun Violence Prevention Act (Brady Law) of 1993 requires a background check be completed within 3 days for all firearm purchases from a FFL holder and that no record be kept of that inquiry. How hard would it be to funnel those background checks into a covert feral database?
When the day arrives, the ferals won't need an exact accounting of all gun owners. All they will have to do is make examples of high profile targeted groups in each state. After that, either the sheeple feebly fall in line or we have CWII.