This reminds me of a dude who... well... look, I'm ashamed to say I know this guy:
Yeah. I don't like him, he's just been... around at some of the campus stuff I've attended. I see him all the time.
Listen, folks. It's like this: get a sheet of plywood and some rope, carry it vertically out into the field, steam the bases of the plants, and then you can make whatever kind of crop circle you like. They did it for Signs, and creative country bumpkins with too much time on their hands have apparently done it for years before. People even do this for money, apparently.
Bottom line: they don't mean anything. Tool-bag.