Artist or Art huh? As much as you would like them separated completely, the former always influences the latter. You can listen to music by hard men, but the tone changes when you know they are hard. See any gangster rap.
I think it is fine to listen to music no matter the crime of the artist, just don't ignore it. Hitler made some pretty sweet paintings, for example. If you still like the product with the veil of their personality hanging over it, then fine. If you feel uneasy, and that's not what you want, then i would suggest not listening. But only judge on the art, and how it makes you feel. Don't not listen on principle or morals or some shit.
I like this UT btw, quality over quantity. For now.