And while many sellers explicitly require background checks before agreeing to sell their goods, there are plenty of participants who simply don’t, which is problematic and dangerous for obvious reasons. “It’s like an unregulated free-for-all,” Shannon Watts, founder of Moms Demand Action, tells Fast Company. For the past year, the advocacy group has been calling for Facebook to implement more-stringent enforcement measures to curb illicit transactions.

And now, after collecting more than 230,000 signatures, those efforts appear to have paid off: Today, Facebook announced that it is enacting new policies on both the social network and Instagram that will make it harder for firearms to fall into the hands of people who shouldn’t have them, like criminals and children. “We will not permit people to post offers to sell regulated items that indicate a willingness to evade or help others evade the law,” says Monika Bickert, head of Facebook’s global policy management, in a statement. Here’s Facebook’s rundown of the new measures:

Any time we receive a report on Facebook about a post promoting the private sale of a commonly regulated item, we will send a message to that person reminding him or her to comply with relevant laws and regulations. We will also limit access to that post to people over the age of 18.

We will require Pages that are primarily used by people to promote the private sale of commonly regulated goods or services to include language that clearly reminds people of the importance of understanding and complying with relevant laws and regulations, and limit access to people over the age of 18 or older if required by applicable law.

We will provide special in-app education on Instagram for those who search for sales or promotions of firearms.

Facebook adds that “private sellers of firearms in the U.S. will not be permitted to specify ‘no background check required,’ nor can they offer to transact across state lines without a licensed firearms dealer.”

“It isn’t an issue selling guns online as long there are backgrounds checks required,” adds Watts. “But we are making huge shifts in the culture around gun violence.”