Hey Crispy, you might want to stop, take a deep breath, and think about this.
No, they might not be very nice individuals from your point of view. But in keeping with your attempt to better your attitude, you ought to at least try to be the bigger man, so to speak. Banning someone for being a part of a clan usually isn't a really great way to work things, especially if they haven't actually done anything extremely ban-worthy as of late.
Just a thought.