Public Knowledge is an advocacy group in the United States.
The mission statement of Public Knowledge is as follows...
"Public Knowledge preserves the openness of the Internet and the public's access to knowledge; promotes creativity through balanced copyright; and upholds and protects the rights of consumers to use innovative technology lawfully."
It aims to keep consumers informed as legislation is written up in the areas of telecommunications, copyright and content consumption; it voices its opinion on legal disputes and so forth in the industries it covers; it works to ensure universal access to affordable and open networks, and so forth.
The group will often release statements that coincide with new bills in the U.S. congress, or major court decisions. It also hosts events that provide a forum for policymakers, the public, industry, and the press to exchange ideas about its core issues.
You could call Public Knowledge a consumer rights group with a main focus on the digital agenda.