Copyright troll Righthaven has run into its biggest legal snag following its formation last year as a vehicle to sue blogs for copyright infringement.

A Colorado federal judge froze some 35 pending lawsuits Thursday, until he determines whether Las Vegas–based Righthaven has legal standing to sue over Denver Post articles.

“Because there are serious questions as to whether my exercise of subject-matter jurisdiction over Righthaven’s claim of copyright infringement is proper, I think it most prudent to stay the proceedings (.pdf) in all pending cases in this district in which Righthaven is the...