Stop Users Uploading Copy Righted Material

Hi,

We have a large wordpress instance with many admin users.

We have been trying to stop our admin users from uploading images that are not ours. In fear of copyright issues, we have tried coaching these users into stopping this. It still happens despite many warnings.

Are there any modules or hacks that can prevent this? Even if there is a checkbox that users must tick stating they own the rights to use the image before uploading. Can you also stop inserting images that are coming from another site (that is not uploaded to the media directory)

Also, is there a way to decrease the media upload limits – the copyrighted images they are using are really big.

This seems to be a reactive approach but educating people is not working.

Cheers,