Some dude called my mom saying he was her brother Carlos from Mexico asking if she remembered him but My uncle lives near us,here in the US and she asked for the his full name and he said My uncle's correct name..... That's all I have to say... Now we r trying to research this number but according to this thing they called from Illinois not Mexico, And we live in CA And as soon as he told my mom his name he hung up.

They're pulling the "relative is in jail/got robbed/stuck in customs and needs money now" scam.  The scammers start by hacking into someone's Facebook account and contacting every friend in that account.  They will call relatives, gathering research and then hitting them with the scam.