I quote a fable from my childhood. It is a bit long so i will only post the moral of the story, as it rings true here.

"A tyrant will always find a pretext for his tyranny, and it is useless for the innocent to try by reasoning to get justice, when the oppressor intends to be unjust."

If you intrested you can read the fable here:
http://www.litscape.com/...he_Wolf_And_The_Lamb.html