“The next time you’re stopped by an authority figure for photographing a federally owned or federally leased building, just hand the law’s agent this declassified 2010 DHS directive that unambiguously states that photographing public buildings from a public place is legal, and that harassing people for doing this is illegal, and that asking photogs to delete or hand over their images or videos is also illegal.
The three-page bulletin reminds officers, agents and employees that, ‘absent reasonable suspicion or probable cause,’ they ‘must allow individuals to photograph the exterior of federally owned or leased facilities from publicly accessible spaces’ like streets, sidewalks, parks and plazas. Even when there seems to be reason to intercede and conduct a ‘field interview,’ the directive says:
Officers should not seize the camera or its contents, and must be cautious not to give such ‘orders’ to a photographer to erase the contents of a camera, as this constitutes a seizure or detention.” (source)