Brian of London has pointed out to me that the Muslim waiting at the entrance of the supermarket does not try to stab the man carrying beer just anywhere: he goes specifically for the neck.
Why? It’s in the Qur’an. “When you meet the unbelievers, strike the necks…” (Qur’an 47:4)
What better epitomizes an unbeliever than an unsuspecting kuffar carrying a six-pack of beer? “O you who believe! Intoxicants, gambling, arrows for seeking luck or decision are an abomination of Satan’s handiwork. So avoid that in order that you may be successful.” (Qur’an 5:90)
And what better time to strike the necks of an alcohol-swilling Infidel than during Ramadan, when Muslims strive to increase their devotion to Allah and hatred of his enemies? Ramadan is a time for Muslims to reinforce their adherence to the Islamic principle of al wala wal bara, that is, “love and hate,” i.e., love for Muslims and hatred for non-Muslims.
Here is al wala wal bara in action.