my phone number isn't listed on my facebook page...but they texted me twice and sent me their yahoo name, when I texted back asking who it was they texted back with OMG My phone is dying.
http://www.andersoncooper.com/2012/05/16/bewa ... ity-theft-scam/
Tighten up the security on your accounts and don't click unknown links. If they've told you their Yahoo ID, report it to Yahoo abuse.