On Wednesday, New York Mayor Michael Bloomberg announced that 90 percent of the traceable guns used in crimes committed in New York City in 2011 came from out of state. Bloomberg, an avid gun control supporter who co-founded an organization called Mayors Against Illegal Guns, specifically called out the lax gun laws in Virginia, South Carolina, and North Carolina, which, Bloomberg claims, make it easier for criminals to acquire guns and bring them up north. The Wall Street Journal notes that Virginia, for example, doesn’t mandate background checks for private firearms transactions.

Bloomberg had a ready answer for those who might criticize him for meddling in other states’ affairs: “To those who say ‘stay out of our state,’ our answer is: We’d love to, just as soon as you stop letting guns seep into the black market and get in the hands of criminals who murder our citizens.” Burn!

I’ve been critical of Bloomberg for his stance on the New York Police Department’s controversial stop-and-frisk program (he’s for it), so it’s only fair that I commend him here. The stop-and-frisk program is, at its core, a gun removal program, with the goal being to stop “suspicious” people on the chance they might be packing heat. But stop-and-frisk is ineffective, invasive, and quite possibly unconstitutional; the NYPD needs a better strategy for getting illegal guns off the streets. The gun numbers Bloomberg cited are legitimate, and he and Police Commissioner Ray Kelly have to try something to get them down. Why not give shaming Virginia a shot?

The governors of Virginia, North Carolina, and other states are, of course, under no obligation to listen to Bloomberg’s remarks—and, honestly, they probably won’t. But, at the very least, the remarks raise awareness—and if Bloomberg backs his comments up with huge campaign donations to anti-gun political candidates in the relevant states, as he has suggested he will, they might do more than that.

Justin Peters writes a crime blog for Slate.