THANK YOU to everyone who posted their experience here!!! I received a voicemail without a name of the organization calling. It might have been said while my voicemail greeting was on, before it started recording. They left something similar to what others heard, "four serious allegations pressed on your name" and to call them back to "discuss this case before taking any legal action against you."
Same as Erin. Useless idiots... I am able to block their phone number. IRS will send a letter to inform you, and not waste the local/ federal resources for few thousand dollars... they simply freeze your bank accounts.