My show sits in an electrician's case, but I'm smart enough to lock it when I'm not using it.
I've only had a few people try to look inside my case - most of them children. It's easy enough to distract a child by giving them "a very important job" to do. IF you tell them the "job" is important, they lose interest in the case, and focus on not ruining the "important job".
When adults try to look in the case . . . bad things happen. I've only had one person try to ruin my show intentionally, he reached into my case while I was trying to get another volunteer on stage. I leaned forward with the case behind me, and tapped the lid with my foot (closing it on his hand). Needless to say, he didn't "put his hand in the cookie jar" again.