The week before the uprising a Coptic chruch was bombed, 40 plus worshippers died and the Muslim Brotherhood was being investigated by Mubarak's police. Then a miracle happened, the "uprising". hundreds if not a thousand Muslim Brethren were released or walked out of jail free, some went East others took to the streets, prison releases no doubt played a role in the riots, looting and general violence, much of it ascribed to common criminals but do we know they were not Brotherhood conscripts? There has never been connection between the timing of the Coptic Church suicide bombing and subsequent events resulting in the uprising which has been portrayed in the west as democratic (whatever that means in an Islamic context- Iran I would remind the reader is "demcoratic" and holds elections as did the USSR.) but given this church arson and the resulting violence I do not think it should be discounted for lack of direct linkage. The Brotherhood does not need to challenge the Egyptian Army it only needs to install Shariah Law as the law of the land.
Death toll from Iraq car bombs rises to 37 (Reuters)
from the article: Egypt officials: 13 killed as Muslims, Christians clash in Cairo