As of this week, Twitter has made sure that federally funded fusion centers can no longer use a powerful social media monitoring tool to spy on users. After the ACLU of California discovered the domestic spy centers had access to this tool, provided by Dataminr (a company partly owned by Twitter), Dataminr was forced to comply with Twitter’s clear rule prohibiting use of data for surveillance.

Twitter sent a letter to the ACLU of California this week confirming that Dataminr has terminated access for all fusion center accounts. The letter also makes clear that Dataminr will no longer provide social media surveillance tools to any local, state, or federal government customer.