Okay, I can't help myself. Here is a link to the letter by Premise Media (the makers of "Expelled") rejecting the lawsuit over using the snippet of "Imagine." Now, christians are saying that it was fair use because the film was commenting on the song. It would appear that, when this was written, they hadn't thought of that just yet. From what I have seen, it looks like they just didn't want to pay an unbeliever for a license to use the song and came up with the "fair use" excuse after the fact.
It seems that a lot of people (both christians and non-christians) are treating this case as if it were about the validity of the claims of the film. It is not. The fact that the producers violated copyright law has nothing to do with the merits (or lack of same) of the film's argument.
I do recognize a bit of irony in a lawsuit over the use of a song that says "imagine no possessions." Was Lennon a hypocrite? Possibly. He could have composed the lyrics just to give his audience what they wanted to hear, but have had no support for the ideas. There is another possibility though. He could have sought to create a possessionless society, but recognized that forfeiting possessions while still in a possession-based society would fail to achieve that end and lead to personal starvation. Me, I like the song, support some of its ideas, but do not want a society without possessions.