Social media surveillance is a growing concern, especially among people who use Facebook and Twitter for activism.
Law enforcement agencies rely on social media tools to track and monitor citizens. According to a study from the Brennan Center for Justice, 156 jurisdictions have spent a total of almost $6 million on these tools since 2010. And the public largely has no idea how they're being used.
In a blog post announcing its new policies, Facebook says it's already taken action against developers who used its platform for surveillance. Geofeedia, for instance, was cut off from Facebook following the ACLU investigation.