What could be more charitable?

What could be more charitable than the work of Amnesty International?  I have heard that Amnesty International UK is hoping to become a charity and I welcome that but I do not know when it will be.  This will give advantages such as being able to accept donations without income tax being taken off.  Also I wonder whether it might help when Amnesty groups are trying to arrange events such as exhibitions, film showings or discussions.  I have heard about such events being refused, with the excuse that it is political or that the pictures in a display might be shocking to people.  (While of course all the violence that comes out in Hollywood films is entertaining and not political or shocking.)