I recommend this vivid piece from the Guardian which relates an exclusive interview with current Muslim Brotherhood members, and recounts the group’s history. Some highlights:

But placating foreign powers was not what Hassan al-Banna founded the movement for in 1928. It was Britain’s presence in Egypt that led to the brotherhood’s creation. Six Egyptian workers employed in the military camps of Ismailiyya in the Suez Canal Zone visited Banna, a young teacher who they had heard preaching in mosques and cafes on the need for “Islamic renewal”.
“Arabs and Muslims have no status and no dignity,” they complained, according to the brotherhood’s official history. “They are no more than mere hirelings belonging to the foreigners … We are unable to perceive the road to action as you perceive it …” Banna later wrote that the Europeans had expropriated the resources of Muslim lands and corrupted them with “murderous germs”: “They imported their half-naked women into these regions, together with their liquors, their theatres, their dance halls, their amusements, their stories, their newspapers, their novels, their whims, their silly games, and their vices … The day must come when the castles of this materialistic civilisation will be laid low upon the heads of their inhabitants.”
…
“There can be no question that genuine democracy must prevail,” Mohammad Mursi, a brotherhood spokesman, wrote in an article for Tuesday’s Guardian. “While the Muslim Brotherhood is unequivocal regarding its basis in Islamic thought, it rejects any attempt to enforce any ideological line upon the Egyptian people.”
Although the Brotherhood appears to have firmly embraced democracy, the means for reconciling that with its religious principles are not entirely clear: the issue of God’s sovereignty versus people’s sovereignty looks to have been fudged rather than resolved.

Main takeaway from the article: there is a mismatch between the Muslim Brotherhood’s current words and its history. That doesn’t prove anything, but it should at least make us wary.