There have been prosecutions resulting in conviction.
Unfortunately, upon appeal the statute has been found to be constitutional (e.g. US v. Danks (1999), US v. Dorsey (2005)).
I should have said that there has never been a prosecution for an otherwise law abiding person under this law. There's no stopping some prosecutor from heaping it on top of other items they charge a person with.
Danks shot at a car, not exactly a case of someone being entrapped by the law.
The Gun Free Zone act was actually declared unconstitutional once, but then amended in 1996 by Congress to correct the problem. If memory serves me right, it ran afoul of the commerce clause somehow and didn't really have anything to do with the substance of the law. I think it has to do with the fact that the gun had to have been involved in interstate commerce i.e. made in a different state than it was used, for the law to be applicable. Thats why the current law says:
It shall be unlawful for any individual knowingly to possess a firearm that has moved in or that otherwise affects interstate or foreign commerce at a place that the individual knows, or has reasonable cause to believe, is a school zone.
Which is interesting, because if you have a S&W made in MA and you live in MA, the law actually doesn't apply.
But back to my main point, the law, if it was actually enforced has the potential to turn literally millions of people into Felons.
1) The law exempts persons with firearm who "are licensed to do so by the state in which the school zone is located". Well, this has literally millions of problems. This means that everyone who goes within 1000 ft of the school who is not licensed by their state is breaking the law.
Not a problem in the Peoples Republik of Massachusetts since you need a license to have an empty piece of brass here. But it means that any person in CT or any other state that does not license long gun owners, who drives by a school on a public road, who does not have a license is breaking the law. It also means that anyone in VT and AZ and NH who allow the unlicensed carry of handguns, who drives by the school with that handgun is in violation of the GFSZA.
2) The ATF does NOT recognize reciprocal agreements between states as being "Licensed to do so by the state in which the school zone is located".
So if you have your non resident FL license with you on a trip down south on I95, unless the gun is
a. Unloaded
b. In a locked container or a locked rack.
You are in violation of the GFSZA every time that I95 passes within 1000 ft of a school.
Please note that this can exceed the requirements of the Safe Passage portion of FOPA, which does not require a locked container if the firearm is in a vehicle where the cargo area is not accessible from inside the car.
So lets get even more imaginative. You are a NH resident. You are going hog hunting in TX. You do not have a NH concealed carry permit because you prefer to OC. You have nothing more than a bolt action rifle in a soft case in the trunk of your car. EVERY time you pass within 1000 ft of a school on your trip to TX, you are committing a Felony. Hmm. bad law.
It gets worse. The law has no exceptions for off duty LEOs or retired LEOs carrying withing the requirements of LEOSA.
Its just crazy.
So, in summary. Ignore the law. You've already broken it if you travel at all with guns. If you happen to take a shot at someone inside a school zone, be warned that this charge will probably be piled on top of the other charges.
But if you are just minding your own business trying to live a law abiding life, then pay attention to the state laws as they apply to schools and you will be fine.
But that's just free advice from some guy on the internets, so do with it what you please.