They don’t know where or when but they did…..?
Check it out:

The Department of Homeland Security flew drones equipped with video cameras over the United States–away from border and coastal areas–for 1,726 hours from fiscal 2011 through this April, according to the Government Accountability Office.

At times, the drones–or Unmanned Aerial Systems (UAS)–were being used for purposes other than border or immigration enforcement. But the GAO does not have a full accounting of when and where the drones were flown, or what they were used for during the flight hours spent in “other airspace.”