#BBCtrending: US mothers criticise Facebook's policy on guns
Remember the "look back" videos that people were sharing on Facebook last week? The videos made a montage of your history on Facebook and were part of the social media network's 10th birthday celebrations.
A group of mothers in the United States has taken the format of the video and used it to campaign against Facebook's policy on guns. Moms Demand Action for Gun Sense in America was formed after 26 children and six adults were killed in a mass shooting at Sandy Hook Elementary School in Newtown, Connecticut in 2012. The group says Facebook is facilitating the "sale" of guns to criminals by allowing firearms to be offered, albeit privately, on the site.
In a statement, a Facebook spokesperson told BBC Trending: "It is not possible to complete transactions on our platform. If you promote an offer involving firearms or other regulated goods, we expect you to make sure you're following all applicable laws and consider carefully the audience for that content."
Anne-Marie Tomchak reports.
Update 5 March 2014: Facebook has announced it is tightening its rules on the sale of firearms on the site. Pages which are flagged up as selling guns, or which primarily sell guns, will be limited to those over the age of 18. Private sellers will not be allowed to specify "no background check required", or offer to sell across state lines without a licensed firearms dealer.
Produced by Neil Meads