Is trading foreign currencies (Euro and Dollar) during times of crisis, such as the current financial crisis in Libya, considered forbidden (haram), especially after the Libyan Dar Al-Ifta (Fatwa Council) issued a fatwa prohibiting it, despite the absence of a clear religious justification for this prohibition?

The basic principle is that currency exchange is permissible. However, if the ruler prohibits it for a public interest or to avert harm, then obedience to him becomes obligatory, because the actions of the ruler are contingent upon the public good. Moreover, a financial crisis may constitute a legitimate justification for this prohibition.