My idea will only work if stored locally.

When accounts are set up in windows, access to any data/files held in the User Profile are locked to that account.

So if another account user tries to access your files...windows stops them.

There's no reason why you can't use a second HDD & assign the folders on it to your User Profile.

The hard part is getting shortcuts to work correctly. I think you'd have to make a shortcut for every film. Each one designed to open a media player & play a single film.

In theory it should work. But there's a lot of swearing between theory & reality