Authorities say Iran has executed a once-exiled journalist over his online work that helped inspire nationwide economic protests in 2017.

Iranian state television and the state-run IRNA news agency said that Ruhollah Zam was hanged early Saturday morning.

In June, a court sentenced Zam to death, saying he had been convicted of “corruption on Earth,” a charge often used in cases involving espionage or attempts to overthrow Iran’s government.

Zam’s website and a channel he created on the popular messaging app Telegram had spread the timings of the protests and embarrassing information about officials that directly challenged Iran’s Shiite theocracy.

Those demonstrations, which began at the end of 2017, represented the biggest challenge to Iran since the 2009 Green Movement protests and set the stage for similar mass unrest in November of last year.