Of course there's been cover ups by the government, CIA etc. but I don't exactly believe in Illuminati and all this crap. All the 'signs' and so called predicted events that happen to coincide with each other on a certain date/time are merely coincidences.
The Illuminati doesn't control anything and even if rappers and such say so or make it seem as though the Illuminati is somewhat real, they're obviously just trying to promote that idea as a way to invoke speculation from people and in turn making their song/whatever more popular.
It's all just in our minds and the whole Illuminati crap is probably just some bullshit someone started and has progressively become worse and worse as people look too much into it and over analyze everything.