Yes, this is actually very hard to deal with, and a very actual debat.
The decentralized constraint I wanted to deal with doesn't allow a lot of control on what is shared.
It could be solved by adding moderators who deletes copyrighted contents (which doesn't leave a lot of content) or by the centralization of the whole system, a digital marketplace like any other one who doesn't need big storage servers to let their user download.
Thanks for reading and for your review !