IMO, most of the so called 'free press' IS being used as a weapon (of mass deception, one might add). It is soft and very subtle weapon, yet very effective; it can be used to 'create public opinion' (for instance, coerce people to belive something, to behave in a certain way etc). Remember Joseph Goebbels and his principles? Well, today most of this principles are still in use, but are more refined and subtle. There is an interesting book covering use of media and PR considering war in Iraq.
Folks who just read newspapers and watch TV and trust all of it, often think they know what is actually happening in the world. In reality, such
people actually haven't got they own opinion at all, but opinion of TV/newspaper editors and people who control (own, if you will) them.