LOS ANGELES - European government officials say the Brussels attacks on March 22 highlight the need to more swiftly share information among governments and intelligence services.

In California, two terrorism experts also point to social media platforms used by extremist organizations, and say technology companies should be included in the effort. The analysts, who monitor hate groups from the U.S., say the threat of violent extremists has become global.

The Brussels attacks, which left more than 30 people dead and hundreds injured, again show the vulnerability of Europe, said Brian Levin, director of the Center for the Study of Hate and Extremism at California State University, San Bernardino. 

Europe is on the doorstep of parts of the Middle East and North Africa that are “controlled by groups by ISIS, or even al-Qaida in certain areas,” said Levin, using an acronym to describe Islamic State. He also said the enclaves provide havens where fighters “can basically study at 'universities' for terror unimpeded.”

Belgian police officers get into a vehicle outside
Belgian police officers get into a vehicle outside a court building where Salah Abdeslam, the top suspect in last year's deadly Paris attacks, was expected to appear before a judge in Brussels, Belgium, March 24, 2016.

There are thought to be far fewer former jihadist fighters in the United States than the thousands believed to be in Europe; however, Federal Bureau of Investigation director James Comey said in October that 900 active terrorist investigations are under way in the country. 

Said Levin, “I think Europe is a harbinger of things to come.”

A more immediate threat comes from social media sites and web-based applications used for terrorist recruiting and encryption, said Rabbi Abraham Cooper of the Simon Wiesenthal Center, which tracks hate and extremist groups online. 

Cooper says the Islamic State is committed to  “understanding what's the latest app, what's the latest way that young people like to communicate with each other, how can we throw off the authorities or lose them at critical moments?” He said the group’s operatives can be found on popular social media sites, where threats by violent extremists blend with hateful rants by racial and religious bigots.

Their postings can spark violence, even among those without formal training, said Levin. “It's the leaderless lone wolves or small cells that are inspired and get technical know-how from the Internet, but have not been able to go in theater and come back.”

He said all countries face a threat of amateurs with powerful homemade weapons, like the bombs used by the Tsarnaev brothers at the Boston Marathon in 2013, which killed three people and injured hundreds.

FILE - An Apple iPhone is pictured next to the log
An Apple iPhone is pictured next to the logo of Apple in Bordeaux, southwestern France, Feb. 26, 2016.

Governments and security agencies can improve coordination, and technology companies can help, these analysts say.

“I think at the end of the day,” said the Wiesenthal Center’s Rabbi Cooper, “it's going to be the CEOs of Apple, Samsung, Facebook, Google, YouTube and Twitter who could help come up with technological strategies that will protect privacy of the good guys and facilitate quick access to data that can mean the difference between life and death in the battle against terrorists.”

Privacy concerns have put some technology companies and the U.S. government at odds, as with the recent demand by U.S. law enforcement that Apple unlock an iPhone used by a suspect in the San Bernardino shootings in December.

That court battle has been on hold since the government said March 21 that it may have a way to unlock the phone itself. With continuing terrorist attacks, the debate over encryption technology is likely to resurface.