So the PPC claim this guy threatened to burn down a venue to prevent a PPC event. And for that, he's suing them for defamation.

But if it's true he was behind the threat, then that literally (even if not legally) makes him a terrorist.

ter·ror·ism

/ˈterəˌrizəm/

noun

the unlawful use of violence and intimidation, especially against civilians, in the pursuit of political aims.

It'll be hilarious if the PPC can prove he was behind the threat and he loses the case, because that will officially prove him a terrorist in court.