The University of California has joined Eolas Technologies in dashing off writs to Facebook, Wal-Mart and the Walt Disney based around four patents for interactive technology.
These include hypermedia display and interaction which were issued to the university and licensed to Eolas, a Texas company chaired by Michael Doyle.
Eolas was founded to help the University of California commercialise technology based around patents Doyle and his team helped develop while he worked at the University, according to Reuters.
Facebook said it will fight the case vigorously.
The case is by no means a done deal. Two of the patents cited in the latest lawsuits were declared invalid in February by a Texas jury in a separate lawsuit.
Eolas settled patent litigation with Microsoft in 2007 for an undisclosed amount. The University of California said at the time its portion of the settlement was $30.4 million.