What would be the definition of a public place?
I recently saw a guy getting serious hassle at Heathrow T5 for taking pictures just airside of the security screening area. As far as I could tell he had taken some photos of his friends still in the queues, but was harassed by two large, armed and uniformed gents, whose loudly expressed opinion was that photography of police or security personnel was forbidden and that he should delete all of the pictures in question.
I would say that taking pictures in that area was foolish, but the police reaction was over the top and heavy handed.