RE: Players' attack by opposing fans: How can this menace be stemmed?

Violence in and outside stadiums has been a problem for as far as I can remember. I think officials are doing a better job to control this inside the arenas, but doing the same outside becomes complicated. For instance, in France, I remember some teams being attacked in their transportation. It's often some small objects or rocks being thrown at the buses, but it can escalate quickly, and arbiters can't be everywhere.