They have lied with just about everything that we have been indoctrinated with as children. The symbolism of the movie the Matrix is incredibly accurate. We have been trapped in an invisible prison based upon the lies they've programmed us with as the very basis for our understanding of the world. It's a prison we can't see even though it's right in front of our eyes, and waking people to the truth is almost impossible due to the massive cognitive dissonance they have with seeing it.