It is our duty to keep our heads cool and minds clear. When the smoke has cleared - then we will grief.
There isn't any time that would be less effective for your goals than right now.
Also, it's like 'teen abstinence' sex ed - you can tell people to refrain all you want, but they're still going to do it. People want to talk about this thing as it's happening; they will find a place to do it regardless.
But we need to do so with sensitivity, too, now.
Edit: I'll go with jacquem's reply to NewNole2001: It can wait a day or two. It can't wait weeks, though. (The Patriot Act was passed less than 7 weeks after 9/11.)
Governments kill way more people than terrorists ever will, but fear those the government tells you to fear...