George Orwell's novel Animal Farm was banned for two reasons. First, the novel was banned (actually, it was a play based upon the novel which was banned) in 1991 in Kenya. The reasoning behind this was the play's/novel's criticism of corrupt leaders. The second time the novel was banned was in 2002. This time, the novel was banned in the schools of the United Arab Emirates. The reasoning behind this ban was the fact that the novel's speaking pigs went against Islamic ideologies and values.
Based upon this, any of the dialogue which takes place between the animals would qualify as a passage which would explain the controversy behind the book.
1. "No animal in England is free.": On top of the fact that an animal is talking, the idea that all "animals" in England are slaves could be seen as controversial (especially given the text was completed in 1945--WWII).
2. "We are born, we are given just so much food as will keep the breath in our bodies, and those of us who are capable of it are forced to work to the last atom of our strength.": Here, one could see the implications that Old Major is making about those in power (or those trying to gain power). Therefore, this passage could be seen as controversial based upon the fact that it alludes to the fact that those in power are simply worried about themselves. (This again speaks to the effects of war.)
3. "Four legs good, two legs better! Four legs good, two legs better! For legs good, two legs better!”: Here, again, the passage speaks to the fact that the oppression by the farmer is over and the animals can now rule themselves. (This again speaks to the outcomes of war.) Outside of that, this is against Islamic views and could certainly be a prominent passage which supported the reasoning behind the ban in the United Arab Emirates.
4. "Yet he is the lord of all animals.": This passage speaks to the fact that those on power (the typically corrupted) are the ones who do not have to work. Instead, they make slaves of those who are under their control. Therefore, this passage criticizes corrupt leaders.
5. "Napoleon, with the dogs following him, now mounted on to the raised portion of the floor where Major had previously stood to deliver his speech.": This passage is said to align with Stalin (a Communist dictator). The fact that this representation is being made during WWII was responsible for the novel being found to be critical of Russia (the USSR).