Edmonton Police Service (EPS) is warning people to double check their bills when selling items on Facebook Marketplace. Police say there have been at least nine reports of counterfeit $100 bills circulating with the same serial number. The suspects are using the bills to pay for cell phones and electronics they buy through Facebook Marketplace transactions, police said on social media. Police are encouraging people to double check $100 bills carefully as real bills have unique serial numbers. EPS has four Buy and Sell Exchange Zones that are equipped with video cameras to record the exchange of online purchases. Other safety tips include never meeting at a secluded place or inviting strangers into your home.