I wonder how long it's going to be before some buncha terrorists tries to drive a truck bomb into an outdoor show...
The media is getting to you. Yes terrorists are a danger, and yes plans of action should exist for any location.
However most high profile terrorists attacks have been anything but random locations or targeting random people.
From the Oklahoma City incident where individuals were intentionaly bombing the regional headquarters of the agency responsible for the Waco incident.
To 9/11 where terrorists intentionaly targeted the World Trade Organization and the pentagon (and the crashed jet going to the whitehouse.)
The World Trade Center was a worldwide symbol of the World Trade Organization and contained many entities part of the world trade organization which manipulates and manages worldwide markets.
Guess what kinda of nations recieve the short end from many of those manipulations? You guessed it, the type of places many of those terrorists were from.
The people on the planes might have been random people, and some of those working in the buildings and emergency personel responding might have been random people, but it was not random people targeted.
I am not making excuses for either of those vicious acts, merely pointing out that it was not just terrorists targeting some random large building. They were specificly targeted for specific reasons, and involved training and funding for over a year prior to specificly attack a specific location.
So yes be ready to deal with terrorists, but don't just drink the koolaid and think every place with lots of people is a likely random target. So far that has not been the case. It could happen with a lone nutjob or two, but so far the types of terrorists successful have been a little more selective in thier targets than just some large cluster of people.