It's possible that one or more of your co-workers just synced their contacts list, with all your email addresses and your phone number, to Facebook. That inform

It's possible that one or more of your co-workers just synced their contacts list, with all your email addresses and your phone number, to Facebook. That information, when intersected with the contacts list, with your phone number, any of your friends or family members synced with Facebook, could provide your details to Facebook (even if Facebook is not 100% sure, it might probably use it).