Caller from this number (he left a message on my answering machine - slight Russian accent) said he was an agent from the IRS and was informing me this was the last notice that the IRS was pressing a lawsuit against me. He wanted me to call another number to discuss (415-799-7748). I didn't call back. Maybe someone else may want to mess with these scammers!
I got a call from this number today, and it went to my voice mail. It just recorded a beginning sentence saying I was being sued by the IRS and to call back. Recoding ended before I got a call back number. Glad I researched.....