The most important part of the teaching/learning process is communication. I am constantly sending messages, emails, comments, and discussion posts to my students. However, a few of them do not read my correspondence. In some cases, a student fails to follow directions on a quiz and invalidates the assessment (such as using a calculator on a quiz when they are not permitted one). In other cases, a student is confused but won't seek help.
It would be helpful to require students to contact me if I know they are not reading my messages. To do so, I would like to be able to lock students out of the "Modules" section on an individual basis. A popup message or webpage would come up that told the student that the teacher has blocked access to that webpage--student should contact the teacher to unlock the page. I don't want to block the student from all of Canvas--I still want them to be able to email me. That is the point of my blocking their access. Once the student has contacted me, I can unlock their access and they can continue with the course.
I realize that this sounds like it is only punitive in nature. However, this is helpful for students who are learning a concept incorrectly and need direction. I have had math students who learn a concept incorrectly but do not try to correct their understanding--they just continue under the assumption that "it will make sense later." Sometimes those students just need to stop and re-learn what they have been missing--they don't understand the gravity of their misconception until it is too late. If I could require them to stop and talk with me, then I might be able to help them learn what they misunderstand.