Why control over the viewability?

Behind the story

When I was pursuing my Master's degree, we had a Visual Analytics assignment. A group of friends and I gathered to work on the assignment together. After completing and submitting the assignment, we went back to our respective places. Later, one of my friends, John, called to inform us that he had received a zero grade due to plagiarism, with a similarity score of 30%. The instructor mentioned that the project's title was exactly the same as someone else's in the class.

However, John was the first one to complete the assignment and had helped many of our friends. He mentioned that he left his locked laptop on his desk and was unsure about any unauthorized access. Subsequently, another friend, Alex, who was also accused of plagiarism for the same reasons, admitted to accessing John's phone without permission. Alex explained that he did open the Google docs to go through the assignment file for reference, as John was busy helping others. Unaware that each project had to be unique, Alex incorporated a lot of details from John's document into his own work. Although Alex worked on the assignment independently, he was still caught for plagiarism due to the identical project title and data file selection for data cleaning.

Although he has locked his iPhone and the Google Docs app with the same passcode, it couldn't help him in this situation. That's when I came up with the idea of having a lock to open specific documents. There were also a few other incidents where someone opened their Google Docs on a laptop to show something to another person, and suddenly the recent files were visible. Sometimes the content may not be very confidential, but the user may not be comfortable if someone takes a glance at it.