The FAA had previously only advised that drone pilots avoid flying near “mobile assets” operated by the Department of Defense and Department of Energy, such as naval warships and truck convoys transporting nuclear materials between US national labs. But the “notice to airmen” alert in January—NOTAM FDC 6/4375—had created the equivalent of roving, 3,000-foot no-fly zones around federal agents’ cars and other vehicles operating in cities and towns across the country. And it didn’t just affect those trying to film federal agents. Because it was practically impossible to ensure compliance with the new flight restrictions, any drone pilot could be at risk during any flight.

“It created a whole lot of fear in the community,” said Vic Moss, CEO and cofounder of the Drone Service Providers Alliance, a drone industry trade association based in Lakewood, Colorado. In a post on March 11, Moss described the FAA flight restriction as posing an “impossible compliance problem” for drone operators, who could end up “ensnared inside a restricted zone with no way of knowing it.”

That may have expedited the government’s next move. On April 15, the FAA removed the no-fly zones by replacing the sweeping flight restrictions with a “national security advisory” titled NOTAM FDC 6/2824. The revised notice dropped all mentions of flight restrictions and criminal charges. It instead “advised” drone pilots to avoid flying near “covered mobile assets” belonging to the Department of Homeland Security and several other federal agencies.