Pretending to be an AARP Rep left threatening message indicating that not returning the call will be considered intentional avoidance of appearing before a magistrate for a federally criminal offense.
You are absolutely correct! This is a scam that is going around now. The IRS would never call or email you; they would only contact you by mail. The caller ID showed up as AARP with phone # 202-215-5408. The guy with an overseas accent left a voice message and was so stupid to twice repeat the phone number to call him back as 201, not 202...!