For every sign warning not to take a photo, the question it begs: why not?
Fairly obvious in the above case, although likely more important to heed the signage when this brothel in Amsterdam’s red light district is actually open for business. For now, not much to protect from documentation (and even if there were, drawn curtains do the job). For each warning not to photograph, a particular authority whose anger would be incurred, and, likely, people who would be interested in obtaining that photo.
With wearable cameras like the Narrative Clip capturing ever more of the people world around us, and formerly-private vehicles become monitored/monetized rentable space and necessitating both internal and external (cue Russian dashcam footage) recording, how possible is it to keep something from being photographed these days, and what are the risks of prohibiting all documentation from a perspective of liability? As storage costs vanish (although paying with your data and granting Google the right to look at your photos could certainly be considered a cost), the threshold of documenting anything and everything lowers to the point where a lack of pictures of a given event (even one that might not have previously been worth documenting) could cause suspicion.
Pics or it didn’t happen, indeed.