Is it normal to be obsessed with people you barely know?

Is it normal that I get obsessed with some people, almost always of the same sex - I am a girl - and I want to know everything about their lives? It is not in a romantic way I am interested, though it is mostly because their phyiscal appearance seems interesting to me.

Sometimes it is girls in my boyfriend's past, some other times just random people, who looked at me in a bad way or somehow made me feel inferior (now particularly a girl of my boyfriend's past who did make me feel inferior). Sounds crazy even to me but I feel my life would be better if they were my friends or were in my life somehow.

I keep looking them up and watching their pictures and trying to find out about them. In comparison I feel so ugly and boring. Cannot stop it, everytime I try, I just stop for a while and then continue doing it, and just as I somehow lost interest in someone's life, someone else appears whom I find appealing.

Not that I wish them harm -though some of them have been bitchy to me- or actually actively stalk them, but I keep looking them up on facebook or internet, never dare to contact them though.

Has anybody been through something similar?

HELP...This drives me crazy because makes me lose time and I keep wanting to be someone else, and feeling bad about what I am and how I look, I am afraid I will end up losing my boyfriend even though he is very supportive and always tells me how wonderful I am.