You may have already been exposed to the work of Freddy Silva on the Art Bell show or many other media outlets. Freddy Silva is considered to be one of the top researches in the arena of crop circle phenomena. In his book, Secrets in the Fields, Freddy pulls the pieces of the picture together regarding what these images mean to mankind in a way that nobody else has done. He also tells of the darker such as disinformation campaigns by the governments of the world.
Now we know that for some people, the subject of Crop Circles raises eyebrows and even a few giggles. After watching this interview, I doubt there will be anyone who could say this is the subject of hallucination or fantasy, there is just too much information documented to disprove them.