Comment by retox

I'm reminded of the apartment doors and coffee machines in a Philip K. Dick story that charged a fee each time they were used, and refused to operate when the protagonist was behind on his rent.

The door refused to open. It said, "Five cents, please." He searched his pockets. No more coins; nothing. "I'll pay you tomorrow," he told the door. Again it remained locked tight. "What I pay you," he informed it, "is in the nature of a gratuity; I don't have to pay you."

"I think otherwise," the door said. "Look in the purchase contract you signed when you bought this conapt."

...he found the contract. Sure enough; payment to his door for opening and shutting constituted a mandatory fee. Not a tip.

"You discover I'm right," the door said. It sounded smug.

From Ubik, by Philip K. Dick. Published by Doubleday in 1969 http://www.technovelgy.com/ct/content.asp?Bnum=1615