An anonymous reader quotes a report from The Guardian: Twitter has blocked federally funded "domestic spy centers" from using a powerful social media monitoring tool after public records revealed that the government had special access to users' information for controversial surveillance efforts. The American Civil Liberties Union of California discovered that so-called fusion centers, which collect intelligence, had access to monitoring technology from Dataminr, an analytics company partially owned by Twitter. The ACLU's records prompted the companies to announce that Dataminr had terminated access for all fusion centers and would no longer provide social media surveillance tools to any local, state or federal government entities. The government centers are partnerships between agencies that work to collect vast amounts of information purportedly to analyze "threats". The spy centers, according to the ACLU, target protesters, journalists and others protected by free speech rights while also racially profiling people deemed "suspicious" by law enforcement. Records that the ACLU obtained uncovered that a fusion center in southern California had access to Dataminr's "geospatial analysis application", which allowed the government to do location-based tracking as well as searches tied to keywords. That means the center could use Dataminr to search billions of tweets and monitor specific demographics or organizations.