My legalistic uncle used to crack down on me a fair bit, for wearing baseball caps in church. They didn't have evil symbols or anything like that, either...mostly just sports teams or movie characters. But he just would not get off my back about it, so I finally spoke to my pastor. He said he didn't know of anything Biblical which forbid people from wearing hats in church, which relieved me. I didn't repeat that to my uncle, but for some reason he eased off after that.