Drones Prohibited Flying Within 3000' of DHS

The FAA just effectively grounded all drone flights. FDC 6/4375 NOTAM published two weeks ago makes it illegal for a drone operator to operate within 3000 feet laterally of any Department of Homeland Security mobile operation in the United States. But given that such locations are not published or marked, operators are typically in unmarked vehicles, etc - it is now impossible for any drone operator anywhere in the United States to be sure they are compliant with the TFR. (It's pretty clear this was published to deter filming of ICE agents in Minneapolis.)

But what about pigeons? https://news.ycombinator.com/item?id=46934867