As Nasking has put in comments, Richard Dawkins and Christopher Hitchens have instructed lawyers to look into the possibility of arresting Pope Benedict XVI on charges of "crimes against humanity". The Guardian says:

The pair argue that Pope Benedict XVI should be arrested when he visits Britain in September and put on trial for his alleged cover-up of sexual abuse in the Catholic church. Last week a letter emerged from 1985 in which the then Cardinal Joseph Ratzinger urged that a paedophilic priest in America not be defrocked for the "good of the universal church".

I think as bad as the actions of the Catholic Chruch are, these sort of moves are counter-productive.

But is the pope immune from prosecution as a head of state?

The Vatican has already suggested the pope is immune from prosecution because he is a head of state. But Dawkins and Hitchens believe that because he is not the head of a state with full United Nations membership, he does not hold immunity and could be arrested when he steps on to British soil.

Interesting times ahead I think.