Crop Circles Man-made?

From a WarnerBros.com Conspiracy Theory newsletter:

There is no convincing evidence that crop circles or any other kind of UGM (Unusual Ground Markings) were made by aliens. There are some reports of lights being seen in and around crop circle sites, and a few videos showing objects flitting over fields. The lights are hardly proof, and the objects in the videos seem to be pieces of foil or paper being tossed about by the wind.

In a deliberate attempt to test crop circle “experts,” a crop circle was faked under the watchful eyes of the media. When cerealogists were called in, they proclaimed it genuine.

Philipp Lenssen on Friday, Mar 31 2006 reg. Conspiracy Theories.