Three gunmen on Wednesday entered the Paris office of Charlie Hebdo, a French satirical magazine, and killed 12 people. The attack was a bloody reminder that journalists are increasingly being targeted by extremists—but bullets are not their only weapon. Militants and other groups are also turning to cyberattacks to silence media outlets they deem hostile to their agendas.

Look no further than the surge in hacks against prominent media that have published critical reports about political leaders and events, only to find themselves fending off retaliatory measures that arrive not through the front door, but from the back door of their information and publishing systems.

The most active group in this regard has been the Syrian Electronic Army (SEA), which coordinates attacks on organization it perceives as hostile to Syrian President Bashar al-Assad. By using a variety of methods – including malware, phishing, defacement and distributed denial of service attacks – the group began levying attacks in 2011 but stepped up its campaign in 2013, when Western media put more focus on the Syrian Civil War.

It remains unclear how closely the SEA and the Syrian government are affiliated.

Reuters, the New York Times, the Huffington Post, the Financial Times, Global Post and the Onion are among those who were infiltrated. The SEA also took credit for hijacking the Associated Press’ Twitter account to erroneously report that the White House had been bombed and U.S. President Obama injured.

The International Business Times was also hacked last month after publishing a report titled “The Syrian Army Is Shrinking, And Assad Is Running Out Of Soldiers.”

Indications are that the attacks will only increase as the Internet gets weaponized. A group calling itself the CyberCaliphate, acting on behalf of the Islamic State terrorist group, hacked the Twitter account of the Albuquerque Journal and WBOC-TV in Salisbury, Maryland on Tuesday, replacing news content with “I love isis.”

There’s also evidence the Islamic State has levied cyberattacks against human rights and media groups operating in Syria.

Signs of the trend are more than anecdotal. The Committee to Protect Journalists announced in 2013 that the number of cyberattacks against media has exploded, particularly in the wake of the Arab Spring protests.

“They are becoming increasingly sophisticated, it’s very cheap to hire criminal hackers to mount such a distributed denial of service attack and digital security, information security is vital,” Robert Mahoney, the group’s deputy director, told Reuters. “We have reports in places in Africa and Asia of journalists coming under attack…We have seen whole newspapers brought down in countries like Ethiopia because there’s been an attack.”

The manhunt for the Paris gunmen is ongoing.