The Aryan Brotherhood has never been infiltrated. So the FBI is lying when they say they have been trying to infiltrate this white supremacist group. The reason why they have never been infiltrated is because they do not exist outside the prison system. Once out, the "members" go on being whatever low live criminal they were before, but there is no organization outside the prison system to infiltrate.
They exist outside of prison.
Up in Idaho, Aryan Nations has a significant presence. I've run into them up there. Here in California they keep a lower profile, but are known to be major Meth distributors working out of Palmdale, San Bernardino, and other shit hole communities. Like cockroaches, you may not see them, but they're there.