I received one of the Scam IRS calls and reported it to the IRS Fraud Dept. If you get one and you have an iPhone5 you can go to your list of recent calls, look for the scam phone number and on the far right you will see a small i. If you hit on this it will bring up some options one of which is to block the call. Hit on that and the number is blocked. I was getting the calls at least
every 3 days and found this is the way to stop them on my cell phone.
