4 ms·Ask HN Darpa red balloon challenge. 1 points by yuanhangw 14y agoany concrete real life user case you can think of?adityar 14y agofinding a "lost" nuclear weapon?yuanhangw 14y agothere is a long list in this whole category, finding missing child, criminal at large, stolen car, etc. I was just wondering if there are other interesting categories that exists