What's difference between recording a CC purchase for $1,000 at "Joe's Gun Shop". And recording a $1,000 CC purchase at "Joe's Gun Shop for a firearm" ?
The first transaction has existed for decades. Most bureaucrats would assume it was a firearm purchase anyway (guilty until proven innocent). And the government has the computational ability to "mine" the data. To be clear, I am not in favor of the additional tracking. However, the government already has access to most of the data if they really want it.
Other than a FTF private cash sale, there is always a chance that "Uncle" will know when you purchased a firearm. That is why they are working so hard to ban private firearm sales, and ban cash money... They can't control what they can't track...
This and if you've ever purchased a firearm deer tag? They know you got guns. Ever visited a gun blog? Bought ammo? Reloading supplies? - they know you got guns.
Zero tracking is best tracking but to act like this NOW gives them some insight into who has what - meh, no, no it's not new.