[Ed. – It also appears to indicate NICS informs states that want the information when a resident has made a long gun purchase — another unadvertised use of NICS. The group Gun Owners of America obtained a heavily redacted copy via FOIA, and the portions of the NICS user manual that indicate these uses were blanked out in that release. It took an unredacted copy, obtained by other means, to reveal the wording that appears to show what Gun Owners of America/Ammoland have concluded.]
When a licensed gun dealer (FFL) runs a gun buyer through NICS, the system checks four (4) databases. These databases are Interstate Identification Index (III), NICS Index, ICE Database, and the National Crime Information Center (NCIC). Located in NCIC data is INTERPOL’s Foreign Fugitive File (FFF). Note U.S. Authorities cannot arrest a subject just for being on the FFF.
According to the unredacted copy of the NICS User Guide … After the sale is complete, the FBI representative will request the buyer’s address and personal information with a call to the FFL, who is compelled to cooperate. The FBI will then pass along the address, and possibly other private information, of the person who legally purchased a firearm to INTERPOL.
Buying a long gun over state lines is legal in the United States. NICS has a built-in program where an anti-gun state can request to be notified whenever their unsuspecting resident buys a long gun across state lines.