It's called 'spoofing' and is highly annoying. I, too, have nomorobo and it's a godsend. That said, we had a call yesterday AM from - supposedly - a local company that is owned by a friend of ours. Odd that he would call the home phone vs DH's cell but I answered anyhow. Nope, some other loser from a different company. There are a few of those that get past the nomorobo but not too many. And if it's not a name I recognize it goes to the machine.