YES, they most definitely do. Sporting events are difficult to secure.
I worked as a security agent at the 1972 Olympics in Munich Germany.
It was not a pretty sight.
Due to the rules of engagement, only 1 in 20 security agents were to be armed. And, those agents were required to keep the weapon concealed.
However, being a cautious individual, I volunteered to be one of the armed agents. I then carried 10 weapons for my team in a backpack so as to conceal them.
When the chaos began, I quickly alerted my team to come and arm themselves so we could protect the athletes. We were just 10 agents with more than 100 athletes to secure.
It was not easy, but we secured our building and held those positions for 72 hours without rest.
If younger, I would do it again in a heartbeat.
Terrorists are evil and so must be eliminated.