Rocco DiPippo at The Antiprotestor Journal has a very interesting post about the DiscoverTheNetwork website, a guide to the political left developed by David Horowitz and others at FrontPage.
They note the following on their website:

The purpose of the DiscoverTheNetwork site is not to stifle free speech but to clarify it. We recognize that people are not always candid in what they say in public life, particularly in the arena of political discourse. Truth in political advertising would be a more accurate description of our intentions in assembling this data.
The problem of deceptive public presentation is common enough to all sides in the political debate but applies with special force to the left, which has a long and well-documented history of dissembling about its agendas.

Take the time to read the numerous comments in response to Rocco’s posting, too. They make for lively reading!