The problem is that what they listen to shouldn’t matter. These fascist fucks shouldn’t have power in the first place, they belong back on 4chan hiding away knowing how unpopular their hateful ideas are.
Fair. The problem with what you propose is that having a space to communicate their 'unpopular' hateful ideas allows them to organise and grow their hate. So no, they shouldn't be on 4chan or wherever as that will only grow their determination. Best to get such places shut down.