To date, the source has been the buyer, so, the user, and the Copyright Board was in a position to set an appropriate levy.
If we're talking about balance in the act, there are licensing bodies and a Copyright Board. Here, in fact, there is an unequal power relationship. It's surprising, given that few people have been able to demonstrate that there was an unequal power relationship in favour of the authors. Regardless, if there is an unequal power relationship, the Copyright Board is able to deal with the issue and determine the terms of the levy.