Its such a scary yet realistic truth, Just wait till there is quad-copters with automatic weapons mounted on them.
Imagine you are pinned down by hostiles behind a broke down brick wall, you and your squadron of 6 vs 12 or so hostiles. Your team carry's 2 quad-copters that can be controlled via live feed and remote control. You launch the copters from behind cover and they are able to fly up and scope in on targets (using a rifle/digital scope mounted on a gyroscope) while constantly moving. It would be nearly impossible to take that thing out of the sky while its flying around. It would also be able to fly multiple stories up and take out snipers and other high ground enemies.