It's also in the same array of, UFOs. They're not ALWAYS aliens, a lot of them are government black op projects. They go out and want to be seen to cover up what they are actually doing, because america doesn't have the mindset to see the truth.
The Illuminati, aren't really "aliens" and if you saw Angels and Demons(even though its a good concept) thats not true either. The Illuminati wants you to believe what you hear and see, and spread that word, to cover up what they're really doing(i dont even know what that is yet), i would have to guess illegal things.
Also, please don't google them and find a website and read what they say. It's probably not an illuminati website. They don't publicily exist, so they wouldnt have a website.