I received a call from this phone number saying I would be in a law suite if I didn't return the call. I did not return the call. They called a second time shortly after the first call. They didn't leave a message the second time.
I got the same call a couple of hours ago: IRS is going to file a lawsuit. It's my understanding that if the IRS wants to connect with anyone, they will use US Mail, not the phone. It's also my understanding that the IRS does not go around suing people. They have legal authority to seize assets without even filing suit, but a whole lot of conversations would take place well prior to anything as drastic as that. Ergo, this kind of call is very likely a scam of some kind.