I think this is a huge threat, personally. Elites have been threatening the water supply for a decade online, even off-handedly. The guy who threatened Savannah, Georgia in "Midnight in the Garden of good and evil" novel, he made it sound so easy. I know it's fiction, but honestly I'm surprised it hasn't happened yet aside from the Flint, MI debacle. I know where my water treatment plant in town is located, easily accessed. People can only survive 3 or so days without water and just like the virus, fear will kill people and the economy, too. Water treatment plants, aquifer locations, reservoirs should all be watched. Methods of contamination should be researched.