This was an interesting article, but isn't the title begging the question? Unless I missed something, no one made any criminal charges, or even raised any suspicion regarding the author's behavior.
All the article says is that there was a sign on the wall. I didn't get the impression it stopped them.
Nothing actually happened. They saw a sign. So the writer gives the impression of being an alarmist worry-wart.
Could this article have been selected for publication so as to fuel the idea that people who are worried are merely overly anxious? The Snowden papers proved that government organizations have been feeding us confusing information to sway public opinion toward obedience to central authority. This may be a good example of it.