At 10:18am 12/8/14 received a call from Novato, CA 415-234-9645 with the message same as others have mentioned. I hung up because IRS is not located in CA and figured it was a scam.
All the below happened to me today 3 times. They called left the same message as below. Phone number 415-234-9645 from California. I called back because of the message. Guy answered and told me the number I called from and my name. He said I need a lawyer. I said for what. He said because they investigated my taxes the last 6 years and I owe a lot of money. There is a case against me. I said I do not have a lawyer. He said I need to get one or I would be arrested.