#12: An Effective Barrier
What makes a good sign good is its ability to communicate a message to all those who read it, I suppose. A number of factors that contribute to this goal are size, font choice, wording, and the ability to demonstrate that the contents of the sign indeed reflect the material reality described.
I’m sorry to say that this tiny sign ticks almost none of the boxes. One could easily break the rule described here without even being aware that they’ve violated the sign or that there was a sign at all. Not to mention that the sign is not accompanied by any means of enforcement.