My friend is talking to an online stranger. stalker maybe?

So a few days ago, my friend's internet broke down. She asked me to go on myspace for her[she was on the phone]. She had a new message and it was from someone with no pic and the display name said "this freakn korean guy" and I asked her if I could open it and read wat it said, but she said just leave it. I got curious, and yes, I am nosy, so I went to the sent mail and read what they were talking about. It was a stranger who was 21, my friend is 14 and he thought she was like 17, and talked to her because he told my friend she has a cute body. They started talking in messages and she actually gave out real info about herself! She gave him her AIM sn and I don't know the rest. I just think it was retarded of her and I don't want her to get stalked or d. I can't confess to her I've been reading her messages since she'll be mad as hell and she's my closest friend. All the other people are either acquaintances or just regular friends, not that close. What do I do?!