the same thing happened to me! I got s text just stating "hi" and when I responded thinking I hadn't saved someone's number I asked who it was and they said "Brianna"
Don't answer this person. It's not a girl. It'd actually a guy who is a predator and after vulnerable people. Do not respond. Report this guy immediately. He gets aggressive when he asks for pictures and you say no. I told him to back off and he said hrwas going to send my pics to all my friends evn though I never sent any.