I accidently did this! I moved away from an area and everyone I know basically did the same thing. So pretty much if it is that area code almost every time it is some spam call. I have been playing the 'clueless old guy' on some of them. It is kind of fun if you are bored. Most of them are left unanswered. Last year a new type showed up, VC guys trying to buy my house (usually well below market rate).