Facebook announced late last week that it will now ban users from arranging the private sale of guns on both Facebook and Instagram. The site previously allowed gun sales under a set of restrictions, but firearms will now join illegal drugs and pharmaceuticals as a completely prohibited item to sell on the social media platform.

The change to its policy has been a long time coming. In March 2014, the site announced new “educational and enforcement measures” for commercial activity on Facebook. However, the social media giant acknowledged the problem of potentially encroaching on peoples’ private speech.

“While we’ve recently heard specific concerns from people about offers for the private sales of firearms, this is one of many areas where we face a difficult challenge balancing individuals’ desire to express themselves on our services, and recognizing that this speech may have consequences elsewhere,” Facebook said in a statement then.

So why did Facebook take action now? It’s likely because of the intensifying debate on the issue gun control in U.S. politics and discourse. Indeed, activists have stepped forward with praise for Facebook’s actions.

“What they’re doing is sending such an incredibly strong, sentinel signal to the world that America is working in the right direction on guns,” Shannon Watts, the founder of Moms Demand Action for Gun Sense in America, told The New York Times. “For them to take a stand and do the right thing gives cover to other businesses to do the right thing.”

Licensed gun dealers can still sell firearms on the site, but there’s no doubt that this new rule is a hugely positive way for Facebook to take some political and social responsibility.