It's very easy for all of us to think all star cheer is actually relevant to anyone on the outside. It's not. I think Pop Warner is more heard of then AS. Sorry that's just how it is. Read any article related to cheer and 97% of the comments will be about high school. The "cheerleading" associated with America is the DCC, they are high profile and travel internationally. If an attack were to happen it would be the NFL, the Olympics, ect.
Home grown terrorists are going to go for soft targets...schools, theatres, offices, hospitals, ect. I am a thousand times more concerned about a hospital being attacked then Dallas Convention Center.
I also think the idea that you are safer with concealed carriers around is false. How is a tactical officer supposed to know who is a friendly in an active shooter situation if you have multiple people shooting at each other? Add in the fact that it's easy to get a cwp in states that allow them.
Situational awareness can go a long way and doesn't involve raising a generation complacent with fear mongering and surveillance. That's why I HATE that stupid "Elf on a Shelf". You're teaching children at a young age that being watched is okay and if you don't fight it you get a present.
If you see something, report it. Don't have your face in your phone 24/7. Check my bag but unless I'm getting ready to go 30,000 ft in the air you can keep your metal detectors and X-ray machines.