The Astroturfs
Organizations and non-profits are referred to as 'astroturf groups' when they have no real grassroots support. These are generally PR firms bankrolled by corporations that are trying to shape public opinion to push favorable state or federal legislation through. Often these groups form legitimate 501c3 non-profit organizations - but their message is anything but reflective of an actual community. If you see a TV commercial or a newspaper ad that is touting "more cable competition" or "more consumer choices", more than likely you are looking at an astroturf campaign message.
Also common are 'front groups', typically these are DC based 'think tanks' that specialize in promoting deregulation and other forms of 'free market' position papers. These are 'think tanks' for hire, which when you 'think' about it, doesn't really seem that ethical. Based in DC, these groups frequently host luncheons and lobby Congress (often at the same time).
Common Cause has produced an excellent report Wolves in Sheep's Clothing covering these groups:
Consumers for Cable Choice (astroturf)
FreedomWorks (think tank)
Progress and Freedom Foundation (think tank)
American Legislative Exchange Council (think tank)
New Millennium Research Council (think tank)
Frontiers of Freedom (think tank)
Keep It Local NJ (astroturf)
Internet Innovation Alliance (astroturf)
MyWireless.org (astroturf)
Others
Telcos Seek to Deceive Bloggers with Cartoon- read article from Media Citizen
Hands Off the Internet, Mike McCurry Sells Out to AT&T - read article from Media Citizen