Fact: If you are carrying a loaded firearm within 1000 feet of any school in a state that has not physically issued you a permit, you are committing a felony.
Fact: The law doesn't give as much leeway for "ignorance" as many think. The law doesn't require that you KNEW you were within 1000 feet of a school, only that a reasonable person in your situation should have known. How long have you lived in the area? Do you have school age children? How long has that school been there, maybe even when you were a kid? Surely you've noticed the flashing school speed limit signs at some point during your travels?
Fact: If you are convicted, you will never legally touch a gun again, for the rest of your life.
Fact: Many states list "places otherwise prohibited by federal law" as a prohibited place under state law. In these states, you would be committing an additional state offense.
Fact: The revised version of the law has been upheld several times. If SCOTUS were to void the current GFSZA law based on its lack of connection to interstate commerce, they would also have to void nearly every other federal criminal statute which relies on a nexus of interstate commerce (all of them!). This would void nearly all of the federal government's police power that it has assumed over the last 110 years. Not going to happen. If you are not familiar with our current system of federal legislation, read the Wickard v. Filburn court case. It was how this "interstate commerce" business got started. Gonzales v Raich is also a good commerce clause case to read. The federal law which prohibits felons from possessing firearms, 922(g), is enforced ALL THE TIME. It relies on the exact same "nexus of commerce" that GFSZA does. Is anyone going to say that it isn't enforceable?
Fact: Peace officers in many states have the authority to make arrests for violations of federal law. Read your state statutes that relate to peace officers, do they have the authority to arrest for federal violations? They do in my state.
Fact: The government is very aware of this law and its effects, read the ATF letter that is included on the Wikipedia page you linked to.
So, if you want to be a law abiding gun owner, don't carry your gun anywhere that would violate GFSZA. Otherwise, every unprosecuted violation committed will be another case of "not enforcing the laws on the books" that the NRA and many "law abiding gun owners" crusade for.
Finally, don't misinterpret my post. I think Fed GFSZA is a terrible law, and it needs to be addressed legislatively. However, that isn't going to happen until all of these "law abiding gun owners" quit hiding from the truth and pretending this law doesn't exist, or that it can't be enforced. So many people refuse to spend thirty minutes to write their congressional representatives about this, and instead choose to trust that the government is benevolent enough to not prosecute them for multiple felony violations of the law. Warrantless checkpoints are okay when the police are looking for drunks. They are okay when the police are checking for immigration status. Don't think for a minute that these checkpoints wont continue to be okay when they are setup in front of schools and "law abiding gun owners" are being removed from their vehicles at gun point to face federal felony charges for GFSZA violations. Many of you know that President HW Bush banned the import of "assault weapons" in 1990 and President Obama continues to do so today. Does anyone know where the authority to ban the importation of firearms not "suitable to sporting purposes" came from? Answer: The Gun Control Act of 1968!!!!!!! This little known, unenforced, clause regarding "sporting purposes" sat on the books for decades before it was enforced, but it is certainly enforced today. I promise, GFSZA has not been forgotten, and will have substantial legal consequences in the future.