Source: Reason

Cato's David Rittgers rounds up cases of terrorist "fusion centers" erring on the side of labeling, well, pretty much everyone, a potential terrorist.

The North Texas Fusion System labeled Muslim lobbyists as a potential threat; a DHS analyst in Wisconsin thought both pro- and anti-abortion activists were worrisome; a Pennsylvania homeland security contractor watched environmental activists, Tea Party groups, and a Second Amendment rally; the Maryland State Police put anti-death penalty and anti-war activists in a federal terrorism database; a fusion center in Missouri thought that all third-party voters and Ron Paul supporters were a threat; and the Department of Homeland Security described half of the American political spectrum as “right wing extremists.”

The ACLU fusion center report and update lay out some good background on these issues, and the Spyfiles report describes how monitoring lawful dissent has become routine for police departments around the nation.

I believe this is the part where right wingers justify including anti-war and environmental groups on these lists, and left wingers justify including Tea Partiers, anti-abortion activists, and Second Amendment advocates.
Article here: http://www.blacklistednews.com/index.php?news_id=12595.