<p><img src="https://images.cointelegraph.com/images/840_aHR0cHM6Ly9zMy5jb2ludGVsZWdyYXBoLmNvbS91cGxvYWRzLzIwMjQtMDcvN2E3MTNlNzUtMGVkMy00YWUwLTkwMTctYTc1OGZmOGJmMDVjLmpwZw==.jpg"></p><p>Everything from radar arrays to acoustic networks that triangulate active shooters can be decentralized and community-owned.</p>