The contents of the Firearms Trace System database maintained by the National Trace Center of the Bureau of Alcohol, Tobacco, Firearms and Explosives shall not be immune from legal process, shall be subject to subpoena or other discovery, shall be admissible as evidence, and may be used, relied on, or disclosed in any manner, and testimony or other evidence may be permitted based on the data, on the same basis as other information, in a civil action in any State (including the District of Columbia) or Federal court or in an administrative proceeding.
This little gotcha is scary. Consider this, you went into your LGS to buy that Glock, because Glock. While there you spot a used Kimber at less than 1/4 its normal price. You buy both.
By law your 4473 can not be used to create a registry. BUT there is a “multi gun purchase” form that must be sent into the ATF if multiple pistols are purchased within a certain time period.
It would not surprise me to learn that that information is in the FTS. It is the case that anytime a trace is done that information goes into the FTS. What else goes into the FTS is an open question.
This opens the FTS for use by the states as a gun registry.