Constitutional law has been botched in this country for some time in my view, but the point of the fourth amendment and other parts of the Bill of Rights was the idea that there would not be dragnets.
That is, if police have probable cause regarding a specific individual, they can investigate, but they cannot investigate an entire neighborhood or city just because laws are being broken. The Constitution gives a nod to the idea that if a behavior does not cause noticeable problems, it should probably be ignored.
In the days of DUI checkpoints, however, the anti-dragnet rule seems to have been weakened, and the use of things like geofencing and stingrays further erodes this prohibition.
In this case, I question the original warrant that allows police to fly over a whole county looking for weed grows. A more traditional interpretation would hold that you can get a warrant to surveil a particular resident or property for weed, but not the whole county.
One wonders what the founders would have thought about marijuana criminalization as well, since under "natural rights" you would be able to do just about anything you could in a state of nature, including growing certain plants.
This is especially dangerous in strict liability crimes like possession, since it is entirely possible to have (on a large property) a patch of marijuana growing without your knowledge.
The war on drugs, like the war on poverty or war on racism, or even the Satanic Panic, is a classic example of a "blank cheque" for the expansion of government power and the police state, and the founding fathers were very clear on not desiring that.