So the weirdest thing happened to me the other day. We were testing to see how high we could get my Phantom 2 Vision+. At around 130 meters, a military jet roars by at very low altitude - about the same height as the quadcopter. We were standing on an empty beach by a lake. The jet came from the direction of the nearby town from the south of the beach, did a small degree turn over the lake sort of going around the beach, then disappeared in the distance. My dad has an interest in the military and identified it as an SK60. The Swedish army uses it to train new pilots. There's a military air base some 20 km away and an underground Saab military jet factory. Naturally we've seen jets in the area before, but at far higher altitudes and certainly not flying directly over houses like that. In 50 years of living here we've never experienced anything like it. So we had a lot of questions. Were they checking out the quadcopter or was it just a very rare coincidence? Can a radar pick up a quadcopter? One theory would be that they noticed it somehow and the training aircraft which could very well already have been in the air was asked to check it out. Another interesting detail: Swedish laws regarding quadcopters are that you can fly them and take photos without permission, but in order to actually publish them (online for example) you need to send them to the military first for approval to avoid any "secrets" being revealed in the photos.