First of all, I NEVER answer any call whose number I don't recognize. My answering machine is on 24/7, so if it's a real call, the caller can identify him/herself. Answering tells the caller, if nothing else, that there's a live person (sucker? victim?) at the other end, even if they're not home at the moment.
On Tuesday, March 1, I got three calls: 206-395-3328, 215-490-3054, and 501-154-1865. These area codes are from Seattle, Philadelphia, and Little Rock, AR. Each one left the SAME EXACT poorly recorded message: "--Revenue Service calling" (your brain is supposed to fill in "Internal" but they never say it). The recording goes on to say that I have several lawsuits against me (!?) and to learn more I should call the number displayed. (I thought you got a summons, not a phone call, when somebody sues you.)
But here's the important part. NO ONE can be in Philly, Seattle, and Little Rock at the same time. There is absolutely NO POINT in checking area codes and prefixes as if they were real phone numbers. The scammers have a program that searches through an area code and immediately picks up phone numbers not yet assigned to anyone and lets the caller use and display them. That's why calling the number back almost always gets you "not in service at this time." The callers who seem to be from all over the country at once are likely ONE PERSON who is not in the U.S. at all. DON'T WASTE TIME CHECKING AREA CODES AND PREFIXES. They won't help you find the perpetrator.