Facebook will now display ads to web users who are not members of its social network, the company announced Thursday, in a bid to significantly expand its online ad network. As The Wall Street Journal reports, Facebook will use cookies, "like" buttons, and other plug-ins embedded on third-party sites to track members and non-members alike. The company says it will be able to better target non-Facebook users and serve relevant ads to them, though its practices have come under criticism from regulators in Europe over privacy concerns. Facebook began displaying a banner notification at the top of its News Feed...