How is facebook adding friends for me without my permission?

[Carly]

After I started using the facebook app on my iphone I have noticed that there are a ton of random people making their way onto my contact list who I certainly did not add. These people are sometimes people who I know and did not want to add, but sometimes are people I dont know but have alot of common friends with. Both my boyfriend and my sister are having the same problem

[Summer Sunshine]

Google

[Liam Murphy]

weird

[Jonathan Orbit]

Someone you know has access to your account and is too afraid to add them on their account so they use yours to look at their profiles

[arisel31]

I'm not sure but I think if they request you facebook makes it so that they can see your activities and you can see theirs even though they are not on your friend's list until you approve them. The reason I know this is because I requested this guy I know and before he accepted me his activity would show up on my homepage. Then a few days later I got the notification that he accepted me. It sucks. Where's my right to deny whoever I want?