It happened to a friend (with a pilot license I precise).
He was flying a small two seat aircraft and got contacted through the radio and for asked if he was ok to do a exercice with military aircraft.
He agreed so soon after two fighter jet arrived on his left and right. To be able to fly at the same speed as him they were almost standing vertically. They directed him for a bit without any radio contact, then thanked him through the radio and left.
They were doing a exercise to direct someone with no radio contact.
So you'll occasionally see two white lines perpendicular to the road at a set internal. A helicopter, drone, or plane can time when a car passes both of these lines and can calculate the average speed of the car.
This info is then relayed to a police car on the ground who then pulls over the driver.
I don't know where op is from but a lot of states, especially in the western US require invasive species tags on any craft over a certain length, like 10 ft. Some also require state registration decals. Idaho is an example of one that takes the invasive species decals and water craft checkpoints very seriously.
The first hint that something was amiss early Wednesday at the Westchester County Airport was the erratic motion of the low-flying Cessna. Confirmation came moments later when security workers approached the aircraft and beer cans fell out of the cabin as the pilot opened the door.
“ According to 49 U.S. Code § 46317, you cannot fly, or attempt to fly, an aircraft without the proper licensure. The penalty for violating this code can be substantial, with a maximum punishment of 3 years in prison and a fine of up to $250,000.”