I can't, as no one can prevent people from sending emails to all their friends with mp3 attachments, or using shared files in dropbox, etc... But here there is a community of people that will consume that media, and the community will have to help to moderate the content as they do on Steemit.com... :) If people see that they put tracks of other artist and they get flagged and the content hidden and their reputation lowered, then they will probably learn the lesson! ;)