Facebook has announced it will take on gun-related posts, shutting them down on minors' pages and blocking posts that sell firearms without a background check or cross state lines.

According to USA Today, groups like Mayors Against Illegal Guns have been lobbying with companies like Starbucks Staples and Facebook for heavier restrictions on gun policies. Facebook will now expand its policy to monitor more than just paid ads and sponsored stories, which have not been allowed to promote weapons at all.

"On the same site that people are sharing birthday parties and family reunions, there are photos of AK-47s," John Feinblatt, chairman of Mayors Against Illegal Guns, told USA Today. "This is not in the bowels of Facebook. This is upfront, center and easy to access."

In a statement released Wednesday, Facebook announced it and Instagram would also aim to educate users on how they handle the sale of regulated items.

"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," the statement read.

Freedom of speech allows users to post virtually anything they want, but images of weapons are typically taken down if it is pointed at the user. On Instagram, a user searching for a post relating to the sale of guns will get an advisory notice.

Gun buyers and sellers have responded on the social media site, saying they find it unfair that firearm enthusiasts are being singled out. A page called "Guns of Sale" has more than 200,000 likes and one user, Stanton McCandlish, 45, of Oakland, Calif., told USA Today he disagrees with Facebook's decision, but can do nothing about it.

"There is no smoking gun here of big groups of Facebook users doing something wrong that requires some regulation," McCandlish said. "But Facebook is a private company, I guess if they want to have restrictive policies that alienate users, they can do that."