Facebook Connect, also called Log in with Facebook, is a set of authentication APIs from Facebook that developers can use to help their users connect and share with such users' Facebook friends (on and off Facebook) and increase engagement for their website or application. When so used, Facebook members can log on to third-party websites, applications, mobile devices and gaming systems with their Facebook identity and, while logged in, can connect with friends via these media and post information and updates to their Facebook profile. But sometimes, especially on lesser known websites, using Facebook's universal login feature may carry security risks, according to research from Princeton University. The tracking scripts documented by Steven Englehardt, Gunes Acar, and Arvind Narayanan represent a small slice of the invisible tracking ecosystem that follows users around the web largely without their knowledge. Facebook says the ability to scrape data through Facebook Connect has been patched. Text:
https://www.wired.com/story/security-risks-of-logging-in-with-facebook/