Are Robo-Calls Driving You Crazy?

It seems to be happening a lot lately, Phone rings, number unfamiliar but looks local. Only to find when you answer that it's another stinkin' robo- call.

When did cell numbers become available to these robo-callers?  I saw a segment recently on how these companies operate. They can literally push a button and call thousands of people at the same time.

Might be one of those "Did you know that your car warranty is about to expire?" or the "We can help you pay off your student loans".

I've gotten to the point where I don't answer if I don't recognize the number calling.  I'm considering  just changing my greeting to "If you don't leave a message, I'll assume you are a robo-caller and block this number"..