I just got a call from this number. A foreign-sounding man claimed that he was from the Treasury department, and that I owed back taxes for 2010 and 2011. He said that the IRS had tried to contact me, and that I hadn't responded, so they had turned over my file to them. He did give me a correct old address of mine, but was suddenly silent when I asked him to verify my Social Security number.
Received an automated call from this number stating that they were pursuing me for fraud (of some form) and wanted me to return their call immediately (to the above number). They claim to be the United States Federate (not any department of the US) .
This is fraud. They claim IRS has filed law suit over income taxes and want to help. Clue - IRS never telephone people, certainly not from Los Angeles.