San Francisco, Aug 28 : Facebook has filed lawsuits against a UK-based app developer for illegally harvesting the data of its users and another developer in the US for operating a fake engagement service on Instagram. Facebook sued MobiBurn, OakSmart Technologies and its founder Fatih Haltas in the High Court of Justice in London for failing to fully comply with its audit request. MobiBurn collected user data from Facebook and other social media companies by paying app developers to install a malicious Software Development Kit (SDK) in their apps, Facebook said in a statement on Thursday. When people installed those apps on their devices, MobiBurn collected information from the devices and requested data from Facebook, including the person's name, time zone, email address and gender. "MobiBurn did not compromise Facebook, instead they used the malicious SDK on the users' devices to collect information," the social network informed. Security researchers first flagged MobiBurn's behaviour as part of Facebook data abuse bounty programme. In a separate case, Facebook sued Nikolay Holper in federal court in San Francisco for operating a fake engagement service known as Nakrutka on Instagram. Holper used a network of bots and automation software to distribute fake likes, comments, views and followers on Instagram "He used different websites to sell fake engagement services to Instagram users," Facebook said. Facebook disabled accounts associated with Holper and his service, formally warned him that he was in violation of our Terms, and sent a cease and desist letter. This is the first time Facebook is pursuing a lawsuit against an app developer in the UK. Facebook has been cracking down on developers after the Cambridge Analytica scandal, which saw the personal data of 87 million users compromised. /IANS