You can, you just can't sell it. They didn't nail these guys for making it, they got them for selling it. If they had kept it in the barn they would have been fine.
The bulk of the Moonshiner stories came during Prohibition and immediately after, before enough distilleries came back on line. Some dry states still had a little here and there fore sale, Oklahoma comes to mind. The bulk of it wasn't all that great, and some was down right dangerous to drink.

If you're in need of some Copper, here it is.
Stills