Why

Danny Hillis, co-founder of Thinking Machines Corporation, allegedly said:

I went to my first computer conference at the New York Hilton about 20 years ago. When somebody there predicted the market for microprocessors would eventually be in the millions, someone else said, "Where are they all going to go? It's not like you need a computer in every doorknob!"

Years later, I went back to the same hotel. I noticed the room keys had been replaced by electronic cards you slide into slots in the doors. There was a computer in every doorknob.