That kind of thing does not happen on moderated filesharing networks.
The best example (and the one I use) is Direct Connect. Hotline is another example. I am sure there are others.
On Direct Connect, you can connect to one of hundreds of sharing hubs, each of which is a mini-network of hundreds of users. If you are sharing too little, or sharing known child porn files, or sharing other undesirable content, automated scripts automatically kickban you temporarily or sometimes permanently.
In addition to this, there are multiple moderators on each hub, who manually go around checking people's files. If there is mislabeling in a user's archive, other users can complain to the mod about it. The mod will speak with the user at fault, and may choose to kickban the user temporarily or permanently.
It is a great system and the quality of the metadata is astounding.