These people used to call from Colorado. After I blocked that area code, now they are calling from NC.

Caller ID says "Alarm Co". Call is computer generated. When answered the message starts, "Hello, we're going to be in your area ..." That's when I hung up.

Don't pick up calls if you don't know who's calling.  You just encourage these morons.  If they leave no voicemail, I block them and then put the number into Google, and it's usually right here.

They are offering to upgrade my alarm system to a newer unit, saying they were in my area at this time.

Turned over their name to a law firm who plans to sue these scammers.