I've been called by them twice. The first time, I answered "4192 nonsecure, identify and authenticate". A confused man asked me "Is this Ray?" I repeat my one line, they hit some buttons on their keypad because I hear the tones. We go along like that for 5 minutes before he hangs up. The Indian callers usually give up in 15 seconds, so that person....was really down there.
The second time, I did something far worse. I had a woman call me, so I turned it into a little naughty time with the phone "What are you wearing?" "Oh, that sounds hot, say it again for me." I was interested to see how far she would take it, and she took it pretty far. So glad it was on her dime.