Radio host Dennis Prager and his business partner Allen Estrin had a big problem on their hands.

It was October, 2013. Several years earlier, the duo—friends for decades—co-founded PragerU, a small digital university for conservatives with a modest audience. Now, a stranger was suing them.

The man, a photographer in Ireland, alleged through a Houston lawyer that PragerU had used one of his photographs in an online educational video without his consent.

Estrin, a former Hollywood screenwriter with little experience navigating the intricacies of digital copyright issues, calls the episode “traumatic.”