Yes. They've even been filmed doing it.
"How are they made?"
With basic mathematics, rope, and wood boards.
"Why are they made?"
For artistic reasons, for a challenge, and for fun.
"Who comes up with the designs and what do they mean if anything?"
The makers come up with the designs; some have meaning (some have been used as advertisements!), and some are purely interesting shapes.
"How many men does it take to make one like this one and how long does it take?"
Usually 2-6 people. A complicated circle can be completed in one night. Most simple ones take a few hours.
"How many people worldwide are involved in making crop circles and why has no one ever ratted out the perpetraters?"
Some hundreds are involved. Some have freely admitted to it. See circlemakers.org. Since it's not a major crime, there is no reason to "rat out" anyone.
I have heard that convincingly debunked as impossible with the larger more complicated designs.
The makers come up with the designs; some have meaning (some have been used as advertisements!)
I have never seen a pic of one used as an advertisement or of any known symbol from human history. I'll check the site you gave address to.
Since it's not a major crime, there is no reason to "rat out" anyone.
I didn't mean that in the sense that a crime was committed but I would in fact think that farmers don't appreciate it and it would be a crime to destroy their property. I used the term only as a manner of speaking since their origins have created so much interest. One would think the creators would take credit, give interviews, write articles and so on and on ...
"Has any man ever been caught in the act of making one?"Etc.
Yes. They've even been filmed doing it."How are they made?"
With basic mathematics, rope, and wood boards.
Spoiler! :-/
For artistic reasons, for a challenge, and for fun.
And for attention, and for financial gain (instant tourist attraction, etc.), and for getting a laugh out of the hordes of "paranormalists" who declare that the prank "couldn't possibly" have been made by any process known to man.
Etc.
Are you aware of any botched circles (i.e., obvious imperfections) and are there pictures of same? Just curious.
Excellent response!