As recent protests over government extremism and economic instability in Iran heated up at the turn of the new year, the government shut down mobile and web networks on December 30, cutting off citizens from apps like Telegram and Instagram used to organize and share information. It was the latest in the Iranian government’s attack on the free internet. Past and present administrations have been ramping up internet censorship for years now, creating a state-controlled national network, according to a new report by the Center for Human Rights in Iran (CHRI), a US-based advocacy group.

The National Internet Network (NIN) was announced back in 2011, under President Mahmoud Ahmadinejad. It was proposed as a “halal” network—the government claimed it was ethical and safe for devout Muslims—as well as a tool for fast and accessible internet. And in 2012, the country’s supreme leader, Ayatollah Ali Khamenei, also created the Supreme Council of Cyberspace, a 27-member committee, to monitor and control the internet and dissemination of information.

By the time the NIN formally launched in 2016 under current President Hassan Rouhani, who ran on a platform of internet access, internet usership in Iran grew from around 77.4 million people in 2015 to 80.2 million people now, according to the report. But getting more Iranians online came with the heavy price of limiting internet freedoms.

It was proposed as a “halal” network

The NIN can filter key words and phrases and send users only to the sites it approved, according to the CHRI report. The government has also limited access to thousands of sites and platforms, including Facebook and YouTube. It is attempting to replace search engines like Google with its own state-approved versions.

Iran has also been able to influence how people use the internet through pricing. While there are private internet service providers (ISPs), they are still under government control, allowing state-run infrastructure companies to set up a tiered plan where access to international internet sites costs more than domestic. This drives traffic away from the global internet and to the NIN.

“The NIN is faster and cheaper because the government wants to isolate Iranians from non-state approved content,” Amir Rashidi, internet security and digital rights researcher at CHRI, told me.

President Rouhani has touted the higher speeds that Iranians can now access thanks to his policies. And his administration has thwarted efforts from more extreme hardliners to completely shut down apps like Telegram, a cloud-based messaging app. But he and internet minister Mohammad Jahromi have been largely silent about censorship, and have limited access to secure messaging apps like Signal and Crypto.cat.

It’s not just internet censorship that Iranians are facing. The report also highlights state-sponsored cyberattacks and phishing schemes. State security agencies like the Islamic Revolutionary Guard Corps, a branch of the armed forces meant to protect the Islamic system, have hacked into individual and private online communications and arrested people on the basis of their content, which is technically illegal under Iranian law.

“If you are a dissident or an activist in Iran, you must be very careful how you conduct your communications and what you say, because someone could always be watching,” Rashidi said.

DDoS attacks, which aim to make specific websites unavailable or limit access to information by flooding them with illegitimate traffic, have become more prominent during politically sensitive times as well, according to the report. During the election in 2016, reformist and centrist candidates like Gaam-e Dovvom faced multiple attacks. The report said many of these are also internal attacks through the government.

Read More: Young Iranians Are Demanding Internet Freedom This Election

These attacks and security breaches are poised to become even more frequent as Iran consolidates the internet further. New regulations require all Iranian internet users to have a single identifier to access the internet, mobile phones, and other devices, allowing the government to access a log of all their activities. International human rights organization, Freedom House, ranked Iran second to last for internet freedom in 2016 (the last was China).

Meanwhile, Iranians are not blind to the extensive surveillance they are facing online. As we’ve reported, many internet users use VPNs and other apps to try and circumvent the censorship. And millions of Iranians have turned to the Toronto-born Psiphon app to use the internet during the protests in December and this month.