When I was like 13 and was learning to play guitar, I learned sooo many songs by Avenged Sevenfold. And then I saw pictures of them playing concerts with the confederate flag, and even had custom confederate flag guitars. I lived a pretty sheltered life and didn't quite understand how big of a deal that was at the time, but it definitely felt a little gross to me. I slowly stopped listening to them.
They did eventually come out and say that they regret doing that, for what it's worth. But I never went back to listening to them.