UFO Encounters or Man-made Hoax

 Sources: http://i.telegraph.co.uk/multimedia/archive/00679/crop404_679706c.jpg and http://en.wikipedia.org/wiki/Crop_circle

Comment: So crop circles are generally described to be geometrically intricate designs found in fields / farms that seem to have appeared overnight. The top image is apparently a coded representation of pi to the 10th decimal place! Many attempts have been made to explain their occurrence and most people seem to have settled for the fact that they are man made hoaxes especially after  Doug Bower and Dave Chorley admitted to using drawing boards to replicate these phenomena. However I still wonder about the Saucer-Nest case in Australia. Is it too much of a stretch to say that some of the earlier recordings might not have easily been done overnight by a group of humans ?