A guy is working in the field and is suddenly surprised by two officials asking for his social security number. He has a reason (I forgot) not to give it. When they leave, the guy is puzzled: there is no path in the vegetation the way they arrived.
Back home, the couple he lives by tells him he may not stay unless he provides the number. (...) He decides to explore the surroundings: from time to time, there is just void in front of him and then the landscape materializes. The guy realizes he lives in a computer simulation and manages to get in touch with the operators who present him with two alternatives: he provides the password or the simulation will be deleted - kind of death.
The guy sets the village on fire. As everyone helps extinguish it, the load is too high for the computer so the computer dumps the program over the network and consequently, the operators lose control over it.
At the end, one operator says: "He left without leaving an address." (I read it in French and the sentence certainly was: "Il est parti sans laisser d'adresse.")
The story is situated during the Cold War and was written before the eighties. There is no anachronism, but a very realistic view of what we today imagine computers can do.