"Why haven't you graded and returned any of my assignments yet this term?"

This is not that situation. The database includes everything including graded assignments. It HELPS teachers find the relevant materials because you don't have to dig through a giant stack instead of doing a Ctrl+F. In fact, you'll cause a ton of students need to leaf through their chunks of old files and gather their past submissions to repeat exactly what you went through for every single class. What you propose is not at all kind or ethical.