Sho(w)e Stopper

Throwing rotten eggs and tomatoes at the performers on stage whom public found boring is something everyone had heard of.
But on 14th December, 2008, Muntazer al-Zaidi, a journalist from al-Baghdadia TV innovated and how! He hurled two shoes at the then US President on his last visit to Iraq during a press conference.
Though it started with Bush, now there seems to be no end. In all the major shoe throwing incidents so far, at the recieving ends have been political leaders of huge status - the American President, the Chinese PM and the Indian Home minister.
If used effectively, such a form of protest can have maximum Yield (= effect/cost*punishment).
A shoe thrown at any political leader becomes a metaphor for dissent and the anger filled up among public. The shoe never misses the target, it always hits the Bull's eye. It gets more media coverage than any other forms of protest and people discuss about it with glee. The video of the shoe thrown at Bush became the most searched for video on YouTube and the incident also led to the development of various flash games.
The chances of punishment are also less because, in order to show how he is great the leader is, he generally tries to cover up his humiliation and forgives the person. The Iraqi journalist who had thrown the shoe at Bush had been sentenced for three years in prison, but now the term has been reduced to one year. In India, not only Jarnail Singh has been 'forgiven' by Mr. Chidambaram, he has also got offers for contesting polls from various political parties. Both these journalists have been hailed as a hero.
In terms of political ramifications, the shoe thrown at Mr. Chidambaram has so far been the most effective. It cost Jagdish Tytler and Sajjan Kumar their Lok Sabha nominations.
And, the time consumed and the cost of throwing shoe is minimal compared to other kinds of protest such as organising rallies, bandhs, hunger strike, etc. You just need an ordinary shoe and no extra wastage of time.
So, why is it so effective?
First of all, any object thrown by a common man at a prominent leader is a symbol for the expression of anger against the leader and the policies of his government.
Secondly, it's an object worn at our feet. When a shoe is thrown, it shows the disregard and disgust for the leader. Its a symbol for one's disrespect towards the person. However much the leader may try to brush the incident aside, the point is conveyed to everyone.
Thirdly, it's an act performed by one among the masses, a journalist or a protestor, people can relate more with it individually.
The more prominent the leader, the better. In the case of Bush, who is infamous around the globe, the news of the incident spread to every part of the world.
Shoe throwing in nothing less than a show stopper!
However, the effect will diminish because of over-use. In order to maintain the novelty of such a form of protest, people must keep improvising. For a start, people must start hitting the targets.