I Am One of the Believers in Your True Call and Work in a Security Inspection Body. at - Jurisprudential Answers - Miscellaneous Issues, Vol 1

Ahmed al-Hasan Response:

It is not permissible to assist an oppressor in any form. Rather, the state of the tyrant must be brought down by every possible means and its pillars undermined, for it is part of Satan's kingdom. It is not permissible to litigate before judges who rule by other than what God has revealed and whom the Proof of God has not authorized to judge between people. But if you are working, to the extent possible, to repel the oppression of some people against others, you must also keep what was stated above in mind. Do not become a helper of an oppressor and tyrant by strengthening his kingdom and authority. Work to assist the oppressed and aid the believer. I ask God to grant you all goodness-His pleasure and Paradise-and to keep all evil from you-His wrath and the Fire. God willing, your reckoning will be easy by virtue of your faith, and a Merciful Lord will admit you into His mercy, for He is the Most Merciful of the merciful.