It is proper Netiquette to be respectful of others. Don't disrespect people.
Respect is a particular point of regard for the feelings and wishes of others you engage. It is a quality of online friendship and its variations, fan and follower.
Social Media contacts are friends. We would not engage them otherwise. Respect is a quality of online friendship. Respect is taking into account the feelings and wishes of others before sharing.
Show regard for the wishes of others when posting because respect is a quality of friendship.