There is a Crop Circle makers organisation with designers , producers and their own web site .
http://www.circlemakers.org/new_documents.html
They say they get permission to make the circles and often make them on commision as adverts.
//After Bower's and Chorley's 1991 statement that they were responsible for many of them, circles started appearing all over the world.[14] To date, approximately 10,000 crop circles have been reported internationally, from locations such as the former Soviet Union, the UK, Japan, the U.S., and Canada. //
" I wouldn't be very pleased by twits coming on to my land "
These people can hardly be described as 'twits'. Most of these patterns are very advanced and sophisticated geometric / mathematical formulas that most of us couldn't understand let alone 'draw' near on perfectly in rough crop.
There's one at Wrekin Hill not far from here. The farmer is moaning it's costing him thousands, but they've hardly destroyed any of the crop itself so that doesn't hold water at all and it is rather beautiful. That being said whoever did it didn't get permission and I'd be extremely annoyed if they did it on my land without asking. That also being said Sugar happens and if the farmer chooses not to turn this unfortunate event to his advantage by charging ( as Naomi's friend planned to do) then that's his bad business sense losing him money.