From the Public Relations Society of America:
http://www.prsa.org/aboutprsa/ethics/ethicalstandardsadvisories/#.VZCUQxqCOK0
http://www.prsa.org/AboutPRSA/Ethics/documents/Ethical%20Standards%20Advisory%20ESA%208.pdf
"Misrepresentation by organizations and individuals using blogs, viral marketing, and anonymous Internet postings with undisclosed sponsorships and/or deceptive or misleading identities or descriptions of goals, causes, tactics, sponsors or participants."