Travel website Hipmunk is battling a patent troll over a patent that covers the display of content in multiple windows.

According to Hipmunk, i2z Technology demanded that Hipmunk negotiate a patent license with the firm by July 2 or face legal action. Hipmunk instead filed suit (below) in San Francisco, asking the court to pre-emptively find that Hipmunk does not infringe on i2z’s technology.