And they’re coming out of the woodwork. Another peer-to-peer software application is warning that many major phone and cable companies – not just Comcast – may be targeting and blocking legal Web traffic.

Vuze, maker of a popular P2P video distribution application, released a preliminary report that sheds light on ISPs’ prevalent practice of throttling communication between users.

Last fall, the Associated Press exposed Comcast for cutting off access to legal file-sharing programs. In response to petitions filed by Free Press and Vuze, the Federal Communications Commission has launched an ongoing investigation, which has included public hearings at Harvard and Stanford universities.

Vuze also launched its own investigation, creating a software plug-in to track network interruptions from reset messages. The rate of interruptions was so alarming, Vuze said it suggested that “network management practices that ‘throttle’ internet traffic are widespread.”

The company is calling on the public to install the Vuze Plug-In to help expose ISPs’ covert scheme to restrict the free flow of Internet traffic.