Intruders install security updates (1998)

The basic idea is that a property deteriorates if not occupied, so when these squatters take over an abandoned property they improve it. The reality of german punk culture often did not follow this ideal: in the worst case it was a sham used by junkies to give an aura of legitimacy to their occupation, in the best case chaotic good punks had a different idea of what "maintained" means compared to more orderly people. The concept also exists in informal settlements unrelated to punk culture: to loosly quote a women living in the Venezuelan Tower of David, a precariat slum: "everything we did here was to live like decent people" and yet it still was a shanty town in an unfinished abandoned office tower. The people living there managed basic utilities for their community, which is impressive, but calling the tower maintained would be farfetched.

Cyberpunk author William Gibson features this concept quite often in his slum ridden dystopia, but it is most prominent at the end of the short story "Red Star, Winter Orbit" which he wrote together with Bruce Sterling. The german translation uses the above mentioned word, but in the english original they describe themselves as "Squatters, I guess you could say." so i don't think there is an english word for this concept, neither for buildings, nor networks.

Not saying it is likely, but from working with production systems that could have come from the stone-age I am too well aware of the possible risks of meddling with a setup that looks obviously wrong or too old to be used anymore, only to realize way too late that it was there for a very good reason.

Basically they were hosting the whole thing in an abandoned building that they were squatting, had somehow managed to get electric power but no internet connection.

So they started scanning for wireless networks and find this network. They manage to get access, and they start configuring some services.

Turns out, this person was not really int tech and had mostly default settings. There were some things that were not installed properly and the signal reception was not that good.

Some of these people look up the owner credendials from the bills (some internet providers used to have you login to the billing website and the internet connection using the same credentials) and go ring to the address, pretend to be the internet company and start doing maintenance.

AFAIK they installed a phone/adsl splitter so that the owner making and receiving phone calls would not drop the line for all the people leeching internet connection and also installed a stronger antenna (for free) which boosted signal for all the people leeching internet connection but also for the owner.

Needless to say, they didn't left the new antenna for the internet owner as a present, even though they probably didn't even realize a single thing (also, they closed any security issue and revoked their own access when they left).