Digital-Vending Services recently filed a patent-infringement lawsuit against the university of phoenix, Walden University, and the Capella Education Company. The lawsuit charges that these online colleges are using patented online course delivery structures. The Chronicle of Higher Education reports:

"Digital-Vending Services, based in Washington, accuses the online institutions of inflicting "irreparable harm" on its business. The company is seeking unspecified damages and an injunction barring the institutions from "further infringement," according to the suit.

Digital-Vending was established in 2003 to protect educational-software patents held by members of the Community Learning and Information Network, a nonprofit group that develops distance-learning applications. Members affiliated with Digital-Vending have ties to the education, defense, software, and aerospace industries."

The lawsuit has been filed in Texas, where course management giant Blackboard recently won a similar suit.