For the recent Edinburgh show, Police Scotland issued an important warning about the nature of what security could expect at the concert: "The main threats to this event are the obsessive fans - who are often oblivious to everyday dangers eg heavy traffic. All normal judgment is lost." We honestly can't argue there, given that once in the presence of One Direction, all "normal judgment" is likely long gone.
The document explained concern over "groups of mid-teens without parents or guardians. Tearful, excitable and potentially emotional." Potentially?