The ATF isn’t all bad. In fact, they had a policy of letting illegal gun purchases go between 2006 and 2011. It ended up getting U.S. Border Patrol Agent Brian Terry killed on December 14, 2010, and let Mexican criminals get enough guns that they were found at over 150 crime scenes where Mexican citizens were either killed or maimed.
Read Operation Fast and Furious: The Forgotten History of the ATF's Notorious Gunwalking Scandal at Ammo.com.