Publication is a method of promulgating copyright. When you publish your ideas/images online one you are not "giving" your image rights to instagram (or to any publisher). In the same way, when you make a telephone call, you are not giving your data to the police and 3rd parties (or the phone company) to listen to. Consumers and producers are both better off with "dumb pipes", than this alternative reality. Businesses are continually trying to exploit their position, and are not beyond unethical/shady/opportunistic behaviour. This incident is a sort of 'Exhibit A'.