Blocking cell signals

[KG4CGC]

It could depend on how they block the signals. If they have a Faraday shield around the school, there is little that the FCC can do about that.

Correct. Some buildings are natural shields.
However, if they are using active blocking methods, that's a big no no. Even prisons are not allowed to do that because they could block legitimate signals.
If the school is making the claim that they are indeed blocking signals when it's just a matter of circumstance, that could also be a violation of some type that could lead to correctional measure be taken on the administration.