They call themselves "IRS", not "The IRS" and their name is "Internal Revenue Services", not "The Internal Revenue Service".  Obvious scam.

This number calls you with an automated voice message stating the IRS is filing a law suit against you. You call the number back and a man who barely speaks any English says he is from Washington (?) and that there is a lawsuit and they want your SS number, etc. Asked to speak with someone who spoke English and asked why they wanted that personal information and they hung up. WATCH OUT!

Robocall to my cellphone. Stated that "IRS was filing a lawsuit against me".  Was told to call 509-587-3082.  Pure [***].  I filed a formal complaint with the Treasury Inspector general at this website:  http://www.treasury.gov/tigta/contact_report_scam_ok.shtml
I suggest anyone getting this phone call to do the same. They are trying to nail these scammers.

Thank you for this information. I've been receiving these calls as well. Sounds like they're trying to take advantage of tax season.

same thing happend to me! I wish they could get in trouble for this! Very scary people out there! Said they are the IRS