Absolutely. My eyes were opened to that when I was troubleshooting my father's webcam over the phone. It kept not working when everything looked like it should. He just failed to let me know about the alert that kept popping up that said "camera is locked by <foo>". Instead, without reading, he just hit the "X", even though I was asking for every step he was performing. Closing a rogue alert isn't even a "step" to most people.
If you are relying on dialogs to keep your users safe, you are doing it wrong. Unfortunately, I don't know what the right answer here is.