Some issues – you need to have enough condensation in the air to draw it out. Note that the description calls for it to be used in the mountainous foggy areas. A truly dry area this will not work as well, if at all.
Also, what happens when the collection ends and the net dries out? Then it collects the dust and animal fecal matter in the dust resulting in water that still needs a purification. Better than no water, but still needs work.
I think this would work awesome in a lot of areas of California where we have a 3rd year drought and minimal rain, but plenty of fog in the early hours.
Arms discourage and keep the invader and plunderer in awe, and preserve order in the world as well as property... mischief would ensue were the law-abiding deprived of the use of them.
- Thomas Paine