BAE's Global Combat Vehicle Systems Division had come up with an electronic system which mimic's Harry Potter's cloak of invisibility. A tank division on the move can possibly be invisible to infrared detectors and other surveilance systems or even mimic a car or herd of cows.
The system consists of individual hexagonal metallic plates placed together around the hull, which are semi-conducters that are capable of being heated and cooled individually to match the surroundings. Earlier systems had huge power requirements, but BAE says they have solved that problem, but are not revealing much detail. The company has built up a library of heat signatures which can be reproduced on the panels. BAE says the system can be scaled up to be used on warships or other large vehicles. This stuff is spooky in the video. This just means there won't be a cow left standing. The worst that can happen to a defending army is they'll all have steak for breakfast. Of course, the cat's out of the bag when the sun comes up.