Anti-gun advocates in California are working to turn in more than a half-million signatures in order to put an initiative on the November ballot to tighten the state’s already extremely strict gun laws.

According to this story from The New York Times, Lt. Gov. Gavin Newsom sponsored the measure, which would make California the first state to require background checks at the point of sale for ammunition.

“What makes guns dangerous is ammunition. Yet we don’t do background checks on ammo,” Newsom said in the story, adding that instituting such background checks would stop criminals and others prohibited from owning firearms from buying ammo for them.

But that’s not all the initiative would do.

Anyone selling ammunition would also have to pass a background check and get a license to do so.

From the story:

“The initiative would also streamline California’s unique program allowing authorities to seize firearms from owners who bought the weapons legally and were later convicted of a felony or a violent misdemeanor, determined to be mentally unstable, or were the subject of a restraining order involving domestic violence.”

“The ballot measure would also require owners to turn in large-capacity ammunition magazines. California already bans the sale of assault-style magazines holding more than 10 bullets but regulations allow those who have that ammunition to keep it.”

“It would also require owners to report lost or stolen guns to law enforcement, among other provisions.”

“Politicians like Newsom need to concentrate on stopping criminals and terrorists, not law-abiding citizens exercising their rights,” said Chuck Michel, co-chairman of the Coalition for Civil Liberties, in a statement.

This story from posits that claims like Newsom’s, who is expected to run for governor in 2018, ignores the fact that criminals are likely to buy their ammunition from the same place they buy their firearms, on the streets through the black market, and that restrictions like this will only cause that underground commerce to increase while restricting law-abiding gun owners.

The Times story says supporters of the initiative expect to turn in about 600,000 signatures to election officials, while only 366,000 valid signatures of registered voters would be required to get it on the ballot.