The Columbine shootings resulted in the delayed broadcast of "Earshot", a Buffy the Vampire Slayer episode, because it featured a student bringing a gun to school. "O", the critically acclaimed modernization of William Shakespeare's Othello, was kept on the shelf until just recently, and then sold off to another distributor to further distance Disney/Miramax from any possible association the film's ending might bring up.
Those last two examples, I believe are backwards. The offending action was meant to horrify the audience, which in turn reinforces the idea that such behavior is wrong. The story is more effective because of the controversy, the alleged tastelessness, and I think we failed in our responsibility to teach the audience something when the opportunity arises. But in the inevitable backlash against Hollywood violence, the only thing to do was shrink back, and in doing so, lend credence to the case for censorship.
That's obviously not what's going on with "Big Trouble" and "Spider-Man", but I was already on the subject, and a secondary issue does apply to all of these:
I think we're agreed that it's inappropriate to laugh at a plane hijacking right about now. But was it okay a few weeks ago? More to the point, does it make any difference to release the film a few months later as opposed to now? Those who would be traumatized or enraged or merely shocked when such a thing happens onscreen are going to have that problem for the rest of their lives. A few months won't give them time to "get over it." That's just not realistic.
Perhaps the darker truth is that they're in the minority - the bulk of us are only peripherally affected by recent events, and will go on with our lives in a few days or weeks as though nothing has happened. Like throwing rocks in a pond - the immediate effects are felt as they ripple outwards, but everything returns to a general calm as the water flows around the disruption, smoothing it's edges through force of erosion. (of course, if your rock bounced it's way down a mountain on it's way to the pond, bringing down with it the weight of an avalanche, that would be different. but following that analogy, a few months time wouldn't make the film any more palatable because we'd all be dead.)
Is it better to live in a jaded culture which routinely puts atrocities behind it, or to die amongst what we think of as more "human," people who let their emotions carry them over the brink of destruction?
I honestly don't have an answer to that one. But I'm leaning towards the first option - we can always blow ourselves up later, but it's hard to take back world destruction if it turns out we don't like it.