Le site facebook.com est-il sûr ?

A friend I hadn't seen in years (& didn't want to) invited me to join facebook. I would never have sought her out. I signed up to see what she wanted, and got a list of people and companies, all of whom I recognized. I thought this was a list of people who were on facebook so I checked the people I knew, expecting to see their facebook page. Instead, I got that list: Their tactic of putting up a list with no instruction was deceptive (I should have known I was "inviting" people). Everyone I "invited" was unhappy about it so I had to do a lot of apologizing. I thought my email password was to protect my privacy so only I could access my email. I am uncomfortable knowing they have access to my private information. I didn't go any further as this was enough.