Oracle has sued Google directly, accusing it of patent infringement through Android.
Several Internet companies, including AOL, Facebook, Google and Yahoo, endorse an alternative that seeks to punish foreign Web sites that engage in copyright infringement through international trade law.
The record labels and movie studios have filed lawsuits against Scour, asserting that it was abetting copyright infringement through Scour Exchange.
Under circumstances involving repeated instances of infringement through the use of the University's computing network, such disciplinary action may include the termination or suspension of network privileges.
They had an arrest warrant for Mr. Dotcom, 37, who was born Kim Schmitz and is accused by United States authorities with criminal copyright infringement through the Web site Megaupload, which he founded.
In a suit filed last month, Vivendi Universal and the EMI Group accused Hummer Winblad Venture Partners of contributing to copyright infringement through Hummer's investment of $13 million in Napster Inc., which is now defunct.
Identities are not easy to find in the virtual world, and the company must track the infringement through Internet service providers, who are often reluctant to reveal the names of their customers.
Even as the major labels of the music industry pursue file traders for copyright infringement through lawsuits and the court of public opinion, Vagrant and many other independent label owners cheer them on.
Often, Ms. Ramirez explained, the practice is aided by a level of secrecy, with the patent-assertion entity filing its claims of infringement through a shell company, so that the subject of a lawsuit does not know that its industry rival is behind the harassment.
