We should report them. See message below from the IRS website:
If you know you don’t owe taxes or have no reason to believe that you do, report the incident to the Treasury Inspector General for Tax Administration (TIGTA) at 1.800.366.4484 or at www.tigta.gov.
You can file a complaint using the FTC Complaint Assistant; choose “Other” and then “Imposter Scams.” If the complaint involves someone impersonating the IRS, include the words “IRS Telephone Scam” in the notes.