I cant believe I will say this but I agree with TNR, just on the warrant side of the issue.
The ATF was using him to get at an organization they wanted to bust and use him to spy, they enticed him to saw a barrel off a shotgun(double barrel or single shot) down to 14" if I remember correctly and paid him like a $150 or something close. Then after he did what they asked they threated to charge him with a felony. Now remember this guy was a Vietnam Vet and had NEVER been in trouble with anyone. They knew he didn't to have the money for a lawyer to fight it so you see how that went
Like with any organization law enforcement will sometimes hide behind the law/badge saying they are doing their job when in fact they are just trying to make a name for themselves, or advance their careers.
There are some really evil individuals in this world even inside the USA and these same agency's that did what they did to his mans family will not even go after those individuals with a 10th of the effort they put into going after this man and his family.
You cannot blame the Judge for signing this warrant because he is going off what information he is being given, its always skewed to so that the organization requesting the warrent gets what they want.