Let's play "What If..." for a moment. What if a not-so-overjoyed fan were to rush onto the field and stab or attempt to stab a player? Do you think the authorities should wait until such a thing happens before putting some safeguards into place? The authorities have no way of knowing someone's intentions until after they have been put into action. Therefore, it makes sense to ban any spectator from rushing onto the playing field during a match. I would think this should apply to any such event anywhere. And before you go saying that they should have excused this particular implulsive individual once they saw what he was about, consider that to have done so would only serve to encourage others who, no matter what their intentions, might do the same. Would you like to have all the matches disrupted by such incidents. No, I didn't think so.