He actually laughed about it, which surprised me big time. However, if he brings a radio or 45 player into the house, he has to ask permission and he didn't ask this time. If he doesn't ask, then he pays the consequence. Usually, I just ask him to remove the item, and he does.
He has to ask permission because otherwise we wouldn't be able to find the walls of the house - we'd just see his hobby stuff. I have been there and done that, but never again! He does have a 3 car garage set up with shelving and a workshop area specifically for his hobbies, so he's not suffering.