The most protested professor in the legal academy is back in the spotlight—this time for comments the conservative academic made last month on the Fox News show hosted by Laura Ingraham that linked impeachment witness Lt. Col. Alexander Vindman to espionage.

It’s just the latest dustup involving longtime University of California, Berkeley School of Law professor John Yoo, who is best known as the author of the controversial so-called “torture memos” from 2002, which argued that interrogation techniques such as waterboarding and sleep deprivation are legal amid the War of Terror.