No caller ID.  Had to answer as I work at a campus switchboard.  I picked up and just listened for a few seconds to the sound of a boiler room operation--lots of operators going over the same spiel at once.

A guy called from this number and asked for one of our Principal Engineers. I didn't recognize the number, because it hasn't previously called us, so I answered the phone. The guy on the other end has a very distinct voice and I recognized it immediately. He calls every day from 2 other phone numbers, so I guess he's found a 3rd number to call from. These are sales calls.

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