Context first
Guerilla growing means: growing on land you don't own, without a fence, without a water connection, without being there daily.
This lesson describes why this kind of growing works the way it does. It does not recommend it, does not instruct in it, and is not legal advice. What is permitted where you live is not stated here – you have to clarify that yourself, and as a rule cultivation is tied to your residence and person.
Why the lesson is in this course anyway: it is the extreme case of the course's central claim. All previous lessons show how controls turn into decisions. Here even the last remnant disappears – whoever doesn't own the site can set nothing up, correct nothing, check nothing daily.
Only the selection remains. And that is exactly why it teaches something.