Yes, I'm sure about it. However, there's a few factors that come into it:
1. The buildings concerned are all fifty feet or more inside the boundary fence and on private property.
2. The place involved is here in Australia and we have laws about interfering with the communications systems themselves. However, jamming them to stop access to private property is seen as a privacy issue and no interference with the communications system as they work perfectly once you're off the property or near it's edge.
The matter hasn't been tested in court yet, but one legal opinion I saw made it clear it was legal as the laws here require either owner approval or a court order to establish any communications equipment on private property, this has usually been seen as towers or cables in the past. But the argument can be made a radio signal is no different to a signal on a cable and as long as the signal isn't totally blocked from reaching the other properties beyond yours, then it's not being interfered with, just being refused access to your property.
It's based on that opinion that they have transmitters that mess up the signal for only thirty feet as the units are installed partway up the building so they can't be got at undetected, and the interference extends to several feet above the roof. Thus someone on the far side of the building can get a signal from the tower, but not in the building or close to it.
