During the three days following the September 12 execution of Iranian wrestling champion Navid Afkari, one of the most significant social dynamics has been taking place on social media, most markedly on Twitter and Instagram.

Iranian political activists and ordinary citizens turned activist, enraged by the injustice they perceive in the wrestling champion's case, posted hundreds of thousands of tweets that probably instigated a political and diplomatic move in the West leading top US and European officials to condemn the Islamic Republic for the killing of the 27-year old man arrested during anti-government protests in 2018 and later accused of murder.

Meanwhile, the event brought about a major change in the media landscape. Until September 12, Instagram, which is the only major social media platform not blocked by the Islamic Republic, was a mostly timid outlet for young Iranians to tell each other about what they had for lunch, or what a great time they had with friends and family.

From the early hours of September 12, as the news of Afkari’s execution broke out, Instagram became visibly politicized.  

"The only solution is an uprising. We are not going to be silenced," said @Noushin.37 on Instagram in Persian on September 12.  

Within hours, the comments turned radical. One user asked: "For how long they are going to spill blood and remain in power?," and another desperate comment coming from the lower depths of frustration said: "I wish somebody dropped a nuclear bomb on Iran and rid Iran and the world of this situation."

Expressing anger on social media following major events such as the downing of a Ukrainian airliner by the revolutionary guards in January was a routine occurrence. But with the execution, a new element emerged on Iranian social media: Revenge.

Instagram user @ni.ii.ll commented: "The only price for awakening is blood. And this ISIS-like government will pay a high price for this." Another user promised: "We owe Khamenei an end like Qaddafi's."

This extent of revenge-seeking is unprecedented not only on Instagram, but across other social media platforms.

Various reports by government officials have said that around 22 million Iranians are on Instagram. Some run profitable businesses on the platform. Nevertheless, hardliners have been pushing for years to ban Instagram like Telegram, which they believe is a lawless platform with some 40 million Iranian users.

Although the change that has taken place on Instagram is eye-catching, yet the most significant political activity by Iranians on social media is playing out on the microblogging platform Twitter. Official figures put the number of Iranians on Twitter at around 11 million. The figure is outdated now as it dates to more than a year ago while Twitter can expand very quickly to new users.

Twitter has always been the most politicized social media platform for Iranians and is blocked by the government. Those on Twitter are generally believed to be more educated and politically minded and some of them are militant enough to continue political debates for days. In terms of "amplification" of social and political issues, Twitter is the platform of choice for those who are politically highly motivated.

Iranian Twitter users have been creating political trends that have influenced politicians such as the President of the United States and the US Secretary of state. Both these politicians have at times tweeted in Persian as a means of messaging Iranians and an effective vehicle for public diplomacy. Afkari's execution was one more indication to many that the regime is out of control and will do anything to intimidate and control the population. More and more tweets called for regime change.

Iranian Twitter users in thousands also began demanding condemnation and action by Western governments, particularly European states, that usually are slower in criticizing Iran than the United States.

But the German ambassador in Tehran tweeted a condemnation of Afkari’s execution on Sunday, September 13 and on Monday it was announced that a planned trip by Iran’s foreign minister Javad Zarif to European capital “was postponed”.

This could be an indication that widespread Twitter messaging had an impact in the Afkari execution case and might have put pressure on Western politicians.

Media experts in Iran fear that effective trending on Twitter, and particularly the politicization and radicalization of Instagram will lead hardliners in Iran to call for a ban on Instagram; the only remaining social media outlet Iranians can still use without enduring the financial and techal burden of acquiring software to circumvent the government's censorship also known as filtering.