An elderly relative who lives alone got a similar call from the "IRS" saying she faced arrest unless she forked over her bank information.
Even though she handled the caller properly you could tell the episode shook her up.
I am a professional tax preparer and Enrolled Agent and our local citizens got hit hard on this last tax season. So many were contacting us (largest tax prep company) that I, for my office, went on the IRS.GOV web site to print out the very clear IRS guideline there; the IRS ONLY USES postal mail for any INITIAL contact PERIOD!
The problem is that the scammers have learned how to 'spoof' the Caller ID system so that the display shows "IRS" and that can be very scary. At least one client came in for whom we had done several years of tax returns, convinced that we had done him wrong and was SERIOUSLY antagonistic. He had tried to call the IRS for HOURS and, of course, got no answer! Showing him the printout AND it on the IRS web site FINALLY got him cooled down.
It took about a 2 week period before the scammers went on to another area code (we think!)
As far as the other CRIMINALs and defrauders of our elderly are concerned, I pray that they end up with incurable diseases and misery. SCUM is too kind a word to apply to them!