Not only is the attempt to sell the sex tape a clear indication of Ruiz's ulterior motive, it is morally wrong. If, in fact, Von Miller didn't know he was being filmed then the tape should be considered a breach of privacy. Every human has a right to privacy, especially in one's own home or in another private location. Ruiz's deceitful actions should be considered unjust and illegal.
Sex is an intimate act between two people. Unless it is pornography it should not be sold or distributed without the consent of both parties involved. This is a violation of privacy. The same can be argued about distributing photos of people or taking photos of people without their consent.
Not only should it be illegal, it already is illegal to sell a sex tape if the other person did not give consent. Not only that but in most places it is illegal to film a sex tape if the other person does not give consent. Consent is an important part of this.
Yes, selling a sex tape in which one participant was unaware he or she was being filmed is a violation of privacy. Filming the act secretly is in itself ethically unacceptable. To sell the content to the public amounts to sexual harassment, and even, it may be argued, outright sexual abuse.