Twitter has stopped US intelligence agencies from accessing Dataminr, a service that trawls through its entire network, and which has acted as an early alert system for terror attacks.
A senior US intelligence official, and others familiar with the matter, confirmed the block, which Twitter has not mentioned publically, according to the Wall Street Journal.
Dataminr, a privately owned company, sifts through Twitter's entire global social network to send out alerts of unfolding terror attacks, political unrest and other significant events to its clients, which include financial bodies and news media.
Twitter owns a five per cent stake in the company, which is the only firm allowed access to Twitter's entire real-time stream of public tweets, taking this information and selling it to clients.
Until recently, Dataminr had also supplied the US intelligence services with alerts, which an official said has made it "an extremely valuable tool". For example, the company alerted the US intelligence community to the November 2015 Paris terror attacks shortly after they began to unfold, and, in March, notified clients about the Brussels attacks 10 minutes before news media did.
But Dataminr executives recently told intelligence agencies that Twitter did not want the company to continue offering its services to them, according to the WSJ. The same senior intelligence official said Twitter seemed to be concerned about the "optics" of appearing too close to the US intelligence services.
Twitter has not commented on why Dataminr was able to provide its service to the government for at least two years, or why that arrangement came to an end.
In a statement, the social media firm said: "Data is largely public and the US government may review public accounts on its own, like any user could."
Twitter has stressed in the past that it is willing to cooperate to some extent with governments and the needs of law enforcement. But on the issue of privacy and transparency, it has also stated that, unless instructed by court order, it will notify users of requests from law enforcement concerning their accounts or tweets.
Social media companies, like Twitter and Facebook, continue to be under pressure from governments to clamp down on radicalisation and extremism on their networks. For Twitter's part, it is in a constant battle to remove extremist accounts created by followers of ISIS and other radical groups.
Twitter's decision to pull its Dataminr service from US intelligence will reportedly not affect the financial sector, news media or its other clients outside the intelligence community.
