With terrorists using social media services and Internet technologies to spread propaganda and gain recruits, U.S. counterterrorism experts are trying to get help from the private sector to combat the messaging.

That’s one of the themes discussed by U.S. national security officers about technology and terrorism during a conference on Thursday in San Francisco hosted by Internet-security and performance company CloudFlare.

Although the general public might believe that many recent terrorist attacks are carried out by people who feel isolated from the rest of the world, many of these attackers “feel anything but alone,” said Jen Easterly, a special assistant to President Obama and the senior director of counterterrorism at the national security council. Easterly said that recent terrorism attacks in places like San Bernardino and Orlando were carried out by people who were “all affiliated in some way to ISIL.”

ISIL refers to the terrorist organization called The Islamic State of Iraq and the Levant, and it’s a also known as ISIS. This group’s reliance on technology is much more sophisticated than the terrorist organization Al-Qaeda, Easterly said, and it’s using social media to spread its message, which includes glossy-recruiting videos that resemble those created by the U.S. military. The lone actors responsible for recent massacres were emboldened by the ISIL-created media they consumed. Although they never physically interacted with the group in places like Iraq and Saudi Arabia, they felt a sense of belonging to ISIL, she said.

John Mulligan, the deputy director of the National Counterterrorism Center, said that the rise of “home-grown actors” has made for a much more unpredictable national security environment and is “extremely difficult” for the government to combat on its own.

Easterly said that after the San Bernadino shootings late last fall, President Obama called on her and her group to facilitate a meeting between government officials and technology companies to address the rise of domestic terrorists and ICIL recruiting. She noted that the U.S. government was working on a “mechanism” to share the information they have on terrorists so that tech companies can figure out ways to prevent communications or the spread of propaganda via their services. Easterly did not elaborate on the specifics of the meeting nor which tech companies participated besides CloudFlare, but said the companies “clearly don’t want that stuff on their system.”

“Our capacity to counter these measures is often very limited,” said Mulligan in reference to the need for assistance from technology companies.

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Easterly commended technology companies like Twitter twtr , Microsoft msft , and Google goog , which she said have all recently implemented or are experimenting with ways to prevent terrorists from communicating with others on their services.

For example, Twitter in July removed terrorist-related tweets on its social messaging service that supported the terrorist attacks in France in which a man drove a truck into a big crowd, killing dozens of people.

Google, through its technology incubator Jigsaw, is also testing technology that displays anti-ICIL messaging and videos on YouTube as well as Google Search when people type in keywords or certain phrases that could indicate someone is looking for pro-ICIL literature and media. Easterly said Google chose to create this technology on its own and that “we don’t tell anybody what to do” in regards to creating specific ways to stop ICIL propaganda.

Still, the two counterterrorism officers conceded that that there is a rift between government and technology companies regarding the balance between national security and privacy. Many companies are hesitant to trust the government when dealing with sensitive data in light of high-profile revelations on government spying activities, like those brought to light by whistleblower Edward Snowden.

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The topic of encryption is also a sensitive topic. The FBI, for example, wanted Apple aapl to create technology to circumvent the tough encryption technology built into a disputed iPhone used by one of the San Bernardino shooters. Numerous technology company sided with Apple on the matter, but ultimately the FBI said it was able to crack into the phone without assistance from Apple.

Easterly said there is no easy solution to pleasing both sides and the topic will carry over to the next Administration after Obama leaves office, remarking, “The American people are going to have to weigh in on that debate.”