Why do complete strangers I met online say I am pretty when they see my pictures..?

[manne]

but not my own 400 friends on my facebook that I do know.

[Stranger]

Online is beat place to tell lies

[john]

They think you are pretty. I have a little advice for you, go to your friend list, delete everybody that you don't know. Facebook can get you in trouble if you have people that you don't know in your friend list.

[Genoveva]

Because they are creeps who assume all young teenage girls (what I'm assuming you are) have incredibly low self esteem and will eat up any compliment given to them so the creep hopes of developing a friendship that will eventually lead to a meeting for sex. On occasion, it will just be a stranger who genuinely thinks you are pretty but they are mostly creeps so stay safe. and make your profile private, don't always post what you're doing ("Going to the mall right now! brb") and limit the amount of photos.