Facebook has sued an analytics firm for misusing its data.
Rankwave has been accused of unlawfully using users' information to sell ads.
Facebook says the South Korean firm failed to co-operate with efforts to verify how compliant it's been with the social media network's policies.
They say Rankwave used more than two dozen mobile applications to track comments and likes on Facebook pages.

Hong Kong court finds tycoon Jimmy Lai guilty in landmark security trial
Ukraine peace talks stretch into second day at start of pivotal week for Europe
Flash floods kill at least 37 people in Morocco's Safi province
'Hero' who disarmed Bondi gunman recovering after surgery, family says
