Copyright law is not based on contracts, and does not require agreement. No one may distribute copies of a copyrighted work without permission from the copyright holder. For instance, in the US, both Persons A and F can be sued because Title 17, Section 501 of the US Code says:
(a) Anyone who violates any of the exclusive rights of the copyright owner ... is an infringer of the copyright or right of the author, as the case may be.
(b) The legal or beneficial owner of an exclusive right under a copyright is entitled ... to institute an action for any infringement of that particular right committed while he or she is the owner of it.
Copyright infringement isn't an issue of violating terms you agreed to with a private entity. Your duty to not infringe copyright was imposed by your country's legislature, who does not require your personal agreement to do that.
