I received a call from this number telling me I defrauded the US government that I was a criminal and that a warrant had been issued for my arrest.  He would NOT tell me, however, what I am supposed to have done.

I received the call as well,  It's that IRS scam.
Just ignore the criminals doing this and for goodness sakes nobody is going to come to anybody's door and arrest anyone.

Good News - It's a scam and safe to ignore
Bad News - once your number somehow draws their attention they will usually repeat the calls, often months later from a different number.

Just had this happen!!freaked me put so I just keep calling n calling them back

i got the call too just now.   I notice there are 3 other reports today alone.    Considering very few people know this reporting site exts they must have made hundreds if not thousands of calls today alone

yes they called me when they found out i am a attorney and threatned with a law suit they  hung up