Drone flight has emerged as a hobby during the 2010s, and many travellers bring their drones to take photos or enjoy the sport of flight at a foreign location.
Photography is restricted or prohibited at many venues, including military and security installations. Many urban locations and airports have a general ban on private drone flight, and restrictions may apply generally out of privacy concerns (watching people in private yards by technical means is forbidden e.g. in Finland).
Drones may also fall under general aviation laws, forbidding unauthorized flight near airfields, higher than some limit etc. or requiring a licence for any flying. Some drones know the local regulations and refuse to fly into restricted areas, but don't rely on that.