Facebook took part this week in key talks with European police agencies on how to stop and eliminate violent and terror-related Islamic jihadist posts, in an evolving battle against such propaganda.
Representatives from the giant social network travelled to The Hague for Thursday's unprecedented talks at Europol's headquarters in the city, officials said Friday.
They were also joined by Instagram officials and police from Britain, France and Belgium, aiming "to identify and secure the swift removal of terrorist and violent extremism content uploaded" on both platforms, Europol said in a statement.
The European police agency has been working with Facebook for the past two years on "reducing access to online propaganda," Vincent Semestre, the head of Europol's Internet Referral Unit, told AFP.
Part of the aim was to find ways of dealing with new trends as well as "how to defend themselves against this kind of abuse".
Facebook has said it is committed "to remove terrorists and posts that support terrorism" whenever they become aware of them and "make their platforms a hostile place for terrorists."
Semestre said that while 99 percent of such posts are identified and stopped "we are really looking into how propagandists are moving around these countermeasures that Facebook has put in place."
With the Islamic State on the brink of defeat in Iraq and Syria, its digital presence has also shrunk.
But Semestre warned that as the caliphate's "production capacity" has diminished its "community has taken on board part of the responsibility to create the content."
This was particularly hard to detect for computer programmes.
"If you this afternoon photoshop and put a mash-up of 10 videos and six pictures on a pdf, you will create a new content that no machine in the world ever saw before," he said.
"It's really a never-ending, evolving" battle which is also moving across platforms.
The talks also aimed to help Europol find possible leads to "trigger an investigation."
They came as the giant social network announced a major change in how its news feed works, saying it would give friends and family priority over advertisers and media posts.