Easier to disperse, possibly, but harder to obtain in the quantities and form needed to disperse.

I get the distinct impression that while security on airliners may be more noticeable there are still gaps quite big enough for trouble to get through.

What is different is that, in the wake of September 11, the likelihood of getting planeloads of people sitting still while they are hijacked is very greatly reduced.

When it was just a question of putting up with a few hours delay in reaching the destination, trying to overcome hijackers would just have been stupid - a high chance of getting yourself and others killed, and also a fair chance of bringing about a crash which wouldn't have happened otherwise. But after the Two Towers and the Pentagon, things are a bit different.

But I'm still pretty sure that unconventional use of relatively small killing mechanisms are much more likely that WMDs. Maybe not box cutters next time, but very likely something like car bombs in carefully targeted places.