When i was on my way to Jakarta on Wednesday, i took a flight from Jogja to Jakarta. When i have sat in the chair, there were two peoples in front of me who used his mobile phone which was equipped with a digital camera to take a picture of one of the flight attendances. She was quite annoyed by the behavior of those passenger because it was done several time and she noticed it because there was a sound like when you had a digital camera taking a snapshots.
Perhaps that's why the vendors didn't take away those sound when you are making a snapshots. It makes the object aware if they were being an object. But that's just the protection from the vendors. The best protection still lies on the person itself. It's called ethics. When people learned and know about ethics, they won't do such things even though they could.