Are you going to denounce the existence of particles and atoms then, just because you can't hear or see then?
Back on topic, the illuminati fascinate me, especially that word logo of theirs. (made up? Possibly.) however, if you did your research, according to the source, their influence does not extend only into pop culture, in fact, majority of it is into politics and corporate sectors.
Basically they're just trying to take over the world. In fact it makes me wonder why you think they would need to reach into pop culture. Any trace of the illuminati in pop culture is probably bogus, as from their motives, there is absolutely no need for them to spread the word through it.