No one has mentioned the most serious issue here! The scenario players on the Al Qeda/taliban side will have turbans and robe like clothing which deflect paintballs. That's cheating!
Seriously though, if the field owner wants to do this scenario, he/she will probably discover quite a few people are uncomfortable with the idea. I personally wouldn't attend a scenario like this. The media might percieve this kind of event as "a bunch of rednecks playing an anti-muslim game".
If a bunch of mostly white paintball players got together to do a "blackhawk down" scenario and half the players made themselves look black, it wouldn't go down to well with the public in general. It would have racism written all over it. The Bin Laden scenario would come off the same way since it would seem to make all muslim or middle easterners out to be "bad guys".
You'd think they would at least wait until Osama gets what he deserves (a well placed bomb or bullet) before even considering a scenario about him.
Chew your food before you swallow and you can be president someday too!