So I'm not sure if this is entirely possible. But it seems like an amazing idea that just struck me.
What if there was a thing that said who has unlocked this content previously. Maybe it could be a button, or maybe it could be at the top right of the unlocked content. The only people who can see it are staff and the person who shared the content.
This would be good because if we have a suspicion of someone leeching, (so not being as obvious of aretard), the staff can check what they are viewing and seeing if they are downloading that content.
Now there are some problems with this, that being that people would still have to use their own judgement if the person is leeching. And sometimes that is not always the best thing to do.