By Nathan Morley
Mr. Zam, who was hanged on Saturday, had been living in exile in France until last year when he was lured back to Tehran by the Islamic Revolutionary Guard Corps.
Soon after his arrival in the country, authorities snatched control of his Telegram channel, which boasted over a million subscribers exchanging stories and opinions about the Iranian government.
After his arrest, he appeared in a series of so-called confessions aired on national television.
His channel and website were used to spread information about the protests in 2017, including their timings and location – the network became a major headache for authorities.
Dozens of people were killed, injured and arrested during nationwide protests.
In June, he was convicted of ‘corruption on Earth’, a frequent charge used in cases which involve threats to the Iranian government.
The French government has described his sentence as "a serious blow to freedom of expression and press freedom in Iran".
In response to the execution, four EU countries have withdrawn from an online business forum in the Iranian capital, Tehran.
The ambassadors boycotting the forum are from France, Germany, Italy and Austria.