I'M A TALK RADIO GEEK SO MANY WON'T KNOW THIS

Some anti-Semitic nut has been calling and getting on talk radio shows since early 2009 and last night I heard him again on The Mark Levin Show.  Inga Barks was the guest host, so Levin himself didn't get a chance to explode but I'm wondering about the perseverance of this caller and why the call screeners haven't wised up.