“The US military is developing software that will let it secretly manipulate social media using fake online personas designed to influence internet conversations and spread pro-American propaganda.”
read it here:
http://www.guardian.co.uk/technology/2011/mar/17/us-spy-operation-social-networks
This is already happening on blogs. The other day on naked capitalism, it appeared that there was a bunch of anti-union posters showed up. Yves checked and all five different posters were coming from the same IP address.