On the morning of September 30, 2011, Predator drones circled thousands of feet above a remote stretch of northern Yemen, monitoring a meeting of senior al-Qaeda militants. The CIA professionals operating the drones were not taking any chances. Moments after a Hellfire missile hit the car carrying “high value targets,” another missile struck it a second time.

According to Jeremy Scahill’s account in Dirty Wars, “When villagers in the area arrived at the scene of the missile strike, they reported that the bodies inside the car had been burned beyond recognition. ... Amid the wreckage, they found a symbol more reliable than a fingerprint in Yemeni culture: the charred rhinoceros-horn handle of a jambiya dagger. There was no doubt that it belonged to Anwar al-Awlaki.”

Five years after al-Awlaki’s death, the case of the American-born radical imam who became the face of the world’s most dangerous al-Qaeda affiliate continues to stir debate over the proper use of force in the war on terror. It shouldn’t.

By the time President Obama gave the order to eliminate al-Awlaki from the battlefield, the Islamist cleric and propagandist had amassed first-hand responsibility for a catalogue of plots commissioned in the service of al-Qaeda in the Arabian Peninsula (AQAP). Before he even left America, al-Awlaki was linked to two future Sept. 11 hijackers, Khalid al-Midhar and Nawaq Alhazmi, who prayed at his San Diego mosque and were seen in long conferences with him. Alhazmi even followed al-Awlaki to his new mosque in Virginia.

In 2009, al-Awlaki was in direct contact with Nidal Hasan before the Army psychiatrist went on a shooting rampage, killing 13 people at Fort Hood, Texas. Al-Awlaki personally directed and supplied the explosives that Umar Farouk Abdulmutallab hid in his underwear and tried to detonate on an airplane from Amsterdam to Detroit on Christmas Day, 2009. Al-Awlaki also began the al-Qaeda magazine Inspire, which includes articles like, “Make a Bomb in the Kitchen of Your Mom.”

Nonetheless, a chorus of critics arose to object to the “targeted assassination” of this notorious leader of external operations for al-Qaeda in the Arabian Peninsula (AQAP). Critics of the drone strike paint Awlaki as little more than a clerical firebrand popular on YouTube who posed no immediate danger. He wasn’t even killed on a battlefield, this argument runs, as if the U.S. government should have kept its finger off the trigger until an enemy that doesn’t wear a uniform took the field in his dress blues. Another argument posited that al-Awlaki, as a U.S. citizen, was denied due process, as if a leader of an enemy force in a unilaterally declared war against the U.S. should expect to enjoy Miranda rights.

The notion that al-Awlaki was a bit player in the jihadist movement – or that targeting him was unwarranted – is simply preposterous. AQAP was the first al-Qaeda franchise to publish in English, and, according to former U.S. Treasury Under Secretary for Terrorism and Financial Intelligence Stuart Levey, al-Awlaki “has involved himself in every aspect of the supply chain of terrorism -- fundraising for terrorist groups, recruiting and training operatives, and planning and ordering attacks on innocents.” His summons to holy war reverberated throughout the global English-speaking Muslim community and his broader message of hatred for the unbelievers, especially Westerners, is among the reasons that the self-styled caliphate attracted more than 30,000 foot soldiers from dozens of nations.

What’s more, Awlaki’s message of “self-starter” violence against the West has outlived him. Ubiquitous on the Internet, al-Awlaki has since his death become the only common thread in a series of terrorist plots. The Times Square bomber Faisal Shahzad and the Boston Marathon bomber Dzhokhar Tsarnaev were both inspired by al-Awlaki’s summons to holy war against the infidel. Recent ISIS-inspired attacks on U.S. soil can also be traced back to al-Awlaki. Mateen was a known Awlaki follower and fan of his online “recruitment videos.”

Before killing 14 people with his wife last year, San Bernardino shooter Syed Farook regularly watched al-Awlaki’s lectures with his neighbor.

Underestimating the potency of al-Awlaki’s influence five years after his death would be a tragedy. The continued targeting of jihadists on the battlefields of the Middle East will reduce the terrorist threat, but not eliminate it. In a report released just last week, CEP detailed 88 U.S. and European extremists who have been directly inspired by al-Awlaki’s calls to jihad. That list will surely grow further unless al-Awlaki’s presence on the Internet is rolled back.

That possibility now exists. CEP and Dartmouth computer science professor Dr. Hany Farid have developed a technology, called eGLYPH, which can efficiently find and remove extremist content that has been determined to violate the terms of service of Internet and social media companies. It works like this. Once a person identifies an image, video or audio recording for removal, the algorithm extracts a distinct digital signature from the content, which is then used to find duplicate uploads across the Internet. Once the most noxious al-Awlaki messages are flagged and removed, they would automatically be discovered and removed whenever a subsequent upload is attempted.

With any luck, public demands for tech firms to curb al-Awlaki’s murderous message online will remind them that security is the precondition of liberty. This moment offers a welcome opportunity for Internet companies to back up their oft-expressed commitment to fight terror with deeds. They should seize it.