"News of their arrest quickly began spreading on social media, and the Ferguson police chief was alerted to their arrests by a reporter for the Los Angeles Times."
The article never claims that the documents are from Snowden. There is likely one or more new whistleblowers leaking documents post-Snowden: this series of articles from The Intercept, the stories in the German press last month, and Jacob Applebaum's TAO Catalog presentation last year.
If stories like this are new to anyone reading this, there is a great book worth checking out. "Rise of the Warrior Cop: The Militarization of America's Police Forces" by Radley Balko, ISBN-13: 9781610392112
Is there a suitable material for a lightweight "roof" you could put over your property that would block aerial photography but still allow sunlight and rain to penetrate?
One could even make it shielded against electromagnetic frequencies. No more drones hacking your wifi!