Shoot them?

No.

Document them at work, have them arrested for destruction of property and fined .

YES.

That field is his income, his living. Margins in farming are ever smaller. That damage to an average British field could well be enough to turn that crop from making a profit, to not making one.

Crop Circles are stunning pieces of artwork - but they are also, imho, criminal damage. No one has the right to do that - regardless of what possible tourist revenue might be generated. If farmers WANTED to generate revenue in that way - they'd do this on a formal basis, call the 'artists' in to do designs (like the stunning Firefox creation) and organize tourist access.

Lots of 2012 references on that website. That tells you all you need to know about those who 'study' crop circles.

I agree with your call for Hoaxers to come clean and stop it.

Something tells me, if all the hoaxers stopped today, and not one unattributed crop circle ever appeared again.....you would still cling to your '20%'.

Like Richard Hoagland clinging to his lunar and martian anomalism. Keep believing the myth and ignore the facts.