answer:I have not seen any such signs in my area but I might guess that drug-seeking behavior is the root of some of these signs in offices. As a former EMT, I can say that there is always the potential for violence in the field. People are unpredictable, especially when injured or under emotional stress. Patients can become combative when being treated if they have a head injury or are under the influence. Not all people handle emergency situations well. Unfortunately they can go off on those there to help.