California Ammunition Serial Number Stupidity

The California legislature has just passed out of committee a bill that would require all handgun ammunition sold in the state after 2007 to have unique serial numbers, which can be traced back to the purchaser. (Article here).

What a dumb idea. As usually is the case with gun control laws, this law will hurt the ammunition manufacturers and legal users, and have no impact on criminals.

Vast stockpiles of un-numbered ammunition exist, and will take years to be expended.
Unless all the other states follow suit, anyone would be able to obtain unmarked ammo by going to a different state.
Even if all US made ammunition is marked, unmarked ammunition will be smuggled in on the black market, just as cocaine, heroin, and illegal weapons are.
Serial numbers on guns have not enabled the police to trace weapons from manufacture to criminal reliably, so why would ammunition serial numbers?