“Have we grown accustomed to having our living space curbed by just anyone?”

“Back in September, a group of Czech artists called EPOS 257 camouflaged themselves as city-workers, went to the Palackeho square in Prague and installed a fence. The fence was left on the square with no apparent intent or explanation. At first, the city council didn’t know about it, and when there were told, they didn’t know how to deal with it – what if somebody put it there for a reason? The fence stayed for 54 days before being removed."

The Guerrilla Innovation blog sees this intervention as a disheartening example of our willingness to cede our public space with little protest - that our individual right to space and freedom are easy to curb.
F.A.D. responds with a more accurate analysis - public space is "deeply conditioned by social norms." If construction fencing is erected, most passers-by will assume it has been placed for a good reason.
EPOS 257 also chose a spot that, while very public, doesn't seem to inconvenience anyone to any high degree. People place a certain level of trust in the visual language of the city in order to navigate its complexity, and while this can be subverted to very interesting ends [see related], I wouldn't draw the same ominous conclusions.