That is a true statement, but when there is also credit card transactions buying the jig, a barrel, a LPK, handguard, trigger and upper.....
Not saying they will do anything about it, but someone posted above that apparently the ATF is going door to door collecting 80%'s that people bought (news to me), why even give them the option?
A cash deal in a parking lot is always best! (Where local rules allow). The law here in Michigan looks like it might be changing to require background checks on private long gun sales soon, which I think many other states have already adopted.