In the case of the general public it is different. A curtain is a highly intuitive instrument for privacy protection, you pull it and it covers the window. Understanding how to secure a technical device such as a webcam is not as easy or intuitive, especially if as another poster mentioned, the device is configured to broadcast automatically. People will almost always stay with the defaulted configuration unless they fully understand the technology, hence the reason wifi routers now come with long cryptic random passwords.