That guy knows all your phone numbers, address, your brother's credit card #s, ALL the information from his phone, his driver's license info, everything. It wouldn't be too difficult for the guy to steal your brother's identity.
Through the info on his phone alone, he knows what kind of a relationship he has with anyone just by reading the text messages, etc. Take any information you have on this guy (phone #, etc.) to the police as soon as possible. Your family should be very aware of the potential trouble that could come from this.








