Internal Revenue Services

Have received phone messages two mornings in a row (9/16/15 and 9/17/15) stating "Internal Revenue Services - The reason of this call is to inform you that IRS is filing lawsuit against you. To get more information about this case file, please call immediately on our department number 310-362-4433, I repeat 310-362-4433."
I performed an internet search on the phone number above and found that others had also been receiving this same message this past week. Since I have never received anything in the mail from the IRS, I did not return the call and presumed that this message is bogus and phishing for personal information.