I've owned,built,operated RC,boats,planes,CL my whole life. With the newer tech things like batteries coreless motors,brushless motors ect. are cheap nowadays. As for drones many are made from things like carbon fiber,foam ect. and so are difficult to detect because of it. They come in kits ready to fly and everywhere in between. Under current laws hobbyist are suppose to not fly over 400 feet and are suppose to be in their line of site while operating them along with them not weighing over 55 lbs. There's other laws regarding RC flight but you'll need to look up all of them for yourself to understand them all. The drones in the news are not complying to the line of site,400 foot altitude,55 lbs part and so the Feds are investigating them because of it is what it seems to me. Most people I fly drones/RC ect with could build what your seeing but I could see it seeming remarkable to those who never built these things.