I thought you would like to know where they based the change in the law from.
Fukking morons!
[url]http://www.atf.treas.gov/press/fy01press/080301serialno.htm[/url]
[url]http://www.atf.treas.gov/regulations/td461.pdf[/url]

DEPARTMENT OF THE TREASURY
Bureau of Alcohol, Tobacco and Firearms
27 CFR Parts 178 and 179 [T.D. ATF–461; Ref: Notice No. 877]RIN 1512–AB84
Identification Markings Placed on Firearms (98R–341P)
AGENCY: Bureau of Alcohol, Tobacco and Firearms (ATF), Department of the Treasury.
ACTION: Final rule, Treasury decision.
SUMMARY: The Bureau of Alcohol, Tobacco and Firearms (ATF) is amending the regulations to prescribe minimum height and depth requirements for identification markings placed on firearms by licensed importers and licensed manufacturers.
Specifically, we are requiring a minimum height of 1 1 ⁄16 inch and a minimum depth of .003 inch for serial numbers and a minimum depth of .003 inch for all other required markings. We
believe that these minimum standards are necessary to ensure that firearms are properly identified in accordance with the law. In addition, the final regulations will facilitate our ability to trace firearms used in crime.
DATES: This rule is effective January 30, 2002.

Serial numbers that are stamped very lightly
on the frame or receiver of the firearm are more susceptible to being easily obliterated, altered, or removed. These problems often hinder our efforts to trace a particular firearm.
The Johns Hopkins Center for Gun Policy and
Research provided us with the following
information:
We have been informed by the Baltimore
Police Department that of the almost 3,700
crime-guns recovered by them in 1998, 15%
had obliterated serial numbers. Nationwide it
is estimated that between 9 and 20 percent
of the crime-guns recovered have had their
serial numbers removed.