Facebook as a Military Weapon?

My fellow puppeteers of sp711 probably already know what I am talking about. Operation Ernest Voice was brought to my attention by Professor Otto last week. It is essentially a military operation, run by CENTCOM, which creates fake online identities to spread pro-American propaganda on social networks such as Facebook, Twitter, etc. First information about OEV were leaked in 2010, which confirmed that this "sock puppet" software was originally used to manipulate online conversations to counter the presence of pro Al-Quaida opinions in Iraq. If you want more detailed information about OEV I really recommend to read the article "Revealed: US spy operation that manipulates social media" in the Guardian.

So what does this mean for our everyday internet experience? Does privacy on the internet even exist? From my personal experience in the way I deal with my online presence, my personal photos, opinions etc. I know that social networks such as Facebook create a feeling of privacy, when really, at least those working at Facebook probably have full control of all the user accounts. Especially being only connected with people I know in real life gives me comfort when posting online. However, if a military operation can spread propaganda in foreign countries, doesn't this mean such operations could also be going on at home? It might not be solely for military reasons but for political manipulations. What for example if operations like these would be used in order to spread false information about certain political parties? Furthermore such operations could be used simply for marketing campaigns in order to promote a product. Our personal information (age, gender, location, preferences, dislikes, interests etc.) is already "safely" stored on our accounts, ready for companies to extract and create suitable advertising campaigns around this information. But how bad is all of this really? Should there be complete privacy online? is it even possible? What do you think?