When might Facebook read the cookies on my computer or device?
Web browsers send any cookies for a particular web domain (ex: facebook.com) to the website each time a machine with those cookies accesses content served from that domain. This means that any facebook.com cookies will be sent to Facebook when any page is accessed at facebook.com. It also means that these cookies are sent to Facebook when someone accesses a third party website that has a connection to facebook.com, like through one of our plugins. Your browser or device may allow you to block these technologies, but you may not be able to use some features on Facebook if you block them.