I once had a series of spam calls that reported their number as being my own phone number.

Made it really easy to spot them, and was very funny.

I used to think that was a dumb move on the part of the scammers, and probably would only be effective in a small town where most of the people you know have the same prefix… Then I realized that most of the successfully scammed victims probably live in those small towns.

Great point! I hadn't thought about that. It's my cell that gets hits like this, so the prefix is extra-irrelevant.

This probably had some logic historically with landlines—a neighbor is calling. It’s an anti-pattern for cell phones in the “wrong” area code. Used to get this a lot. Rarely today.