Plenty of freedom of speech arguments here. Quite funny actually. All of us reacting so strongly to a flash that I personally find neither offensive (nor notable). Plus, it's recreation of the events are surprisingly inaccurate. For all I know, only the names have anything in common (heck the character you played wasn't even really Asian, let alone an image of the killer). If it wasn't for that, it could easily be mistaken for something fictional. Obviously a cheap (and effective) attempt to get some attention.
Also, I would like to add two other bits of information to the rest of you who claim absolute freedom of speech.
1. Does anyone recall the yelling "Fire!" in the theater house argument? Not very applicable to this case, but it does point out we do need to understand self-limitation. If you're too dumb to figure out what it is, then try it at your local theater! (No really don't just think about it.)
2. From what I did see in the game, it almost seems like a vague simulator. Oh! How easily could we could cross the line from 'offensive game' to 'training aid' for future shootings. Yeah, we have the right of free speech, but the government has the right to arrest those who 'promote terrorism' and crap. A slippery slope argument, yes, but recall what happened in March 2003 (and still today).
In retrospect, I guess argument 2 isn't completely true, since there is a 'suicide bombing' game somewhere on this site as well. Hmm. I'm almost tempted to see how many games like this can be made on the site before the FBI takes notice and begins operations to investigate. Maybe we are innocent, but I'd rather not have my life interrupted.
To make a long story short, I vote take it down. If it does get taken down or not, I don't care.
Well, have fun demeaning each other and spouting your arguments, I got better things to do. Man why do I waste my time typing this? Not too many people will read it (nor understand it :P)