is using mail id/fb id while logging safe?

Question

While logging in most websites need our mail id or fb id. Is there any assurance that our personal info is not being compromised?

Nithya Mathan · Answer

I think this is the short way for logging in... but I didn't suggest to log in to the websites because there we have some issues with that -they have our mail id and FB id information -they publish the ads on our FB id and sending unwanted messages to our mails... These methods for having our information but mail is the suggested way to login to different websites.