Specifically, all three companies granted access to a developer tool called Geofeedia which allows users to see the geographic origin of social media posts and has been employed by more than 500 law enforcement organizations to track protesters in real time.

Law enforcement's ability to monitor the online activities of protesters could have a chilling effect on First Amendment rights, the post asserts. "These platforms need to be doing more to protect the free speech rights of activists of color and stop facilitating their surveillance by police," Nicole Ozer, technology and civil liberties policy director for the ACLU of California, told the Washington Post. "The ACLU shouldn't have to tell Facebook or Twitter what their own developers are doing. The companies need to enact strong public policies and robust auditing procedures to ensure their platforms aren't being used for discriminatory surveillance."

Based on information in the @ACLU's report, we are immediately suspending @Geofeedia's commercial access to Twitter data. — Policy (@policy) October 11, 2016

Twitter released the above statement, Facebook (which owns Instagram) provided Engadget with the following comment, "This developer only had access to data that people chose to make public. Its access was subject to the limitations in our Platform Policy, which outlines what we expect from developers that receive data using the Facebook Platform. If a developer uses our APIs in a way that has not been authorized, we will take swift action to stop them and we will end our relationship altogether if necessary."

All three companies have sought to restrict Geofeedia's access to their data in recent weeks. Instagram and Facebook reportedly terminated access to their respective APIs on September 19th. Twitter renegotiated their contract with the subsidiary that granted Geofeedia access with additional terms to safeguard against surveillance and sent the analytics company a cease and desist letter on Monday before shutting down access altogether earlier today.