On December 28th, 2017, anti-government protests in Iran broke out over rising food prices. Just two days later they escalated after three were killed and others wounded by police. To dampen the spreading of the protests, the government shut down internet access in the country and blamed external forces like the United States, Britain, Israel, Saudi Arabia and warned those who “disrupt the order and break the law must be responsible for their behavior and pay the price,” and that “fear and terror will definitely be confronted.”
Protests continued sporadically towards the end of 2018 and started again in November of 2019 over quadrupling fuel prices. Unrest in Iran seems to coincide with pro-government rallies celebrating the current government's anniversary, which is December 30th.
NetBlocks, an internet monitoring service confirmed the internet shutdown affecting different regions of Iran, showing a line graph of network connectivity in Iran that shows steep usage drops beginning at 6:30am on the 25th of December.
Confirmed: Evidence of mobile internet disruption in parts of #Iran beginning ~6:30 a.m. (03:00 UTC); real-time network data show two distinct drops in connectivity this morning amid reports of regional outages; incident ongoing 📉 #Internet4Iran
— NetBlocks.org (@netblocks) December 25, 2019
Iran's usage of internet outages as an anti-protest tactic is not new. Back in 2018, UN human rights experts urged Iran to respect the rights of protesters and end the internet crackdown. Iran's internet is already censored. State news has been banned from covering protests.
Telegram messenger has been instrumental in spreading news and also organizing protests in Iran. The encrypted chat service has been banned specifically by the Iranian government after Telegram refused to close channels the government had requested.
Iranians are currently in the midst of another wave of protests with Amnesty International saying at least 304 people were killed and thousands arrested over the last month and a half. Reuters put the death toll at 1,500, based on information from unnamed ministry officials.