So, under the ruling, the ATF can demand anything so long as it's part of an "ongoing criminal investigation." In this case, the definition of "ongoing criminal investigation" is anything for which the ATF wants to gather information.
I wasn't really happy with the court's rather vague logic in getting around the part of 18 U.S.C. 923(g)(3)(B)
that specifically and only mentions "pistols and revolvers."
Correct me if I'm foggy, but doesn't the Rehberg amendment cut off funding for this practice anyway?