Earlier this year, Gibbz Arms was supopsedly insinuating that Magpul stole their design and named it M-LOK. Magpul is quickly fired back and filed a lawsuit against Gibbz Arms.
You can read more about it from Soldier Systems
http://soldiersystems.net/2016/03/07/the-gama-m-lok-battle-heats-up-as-magpul-files-suit-against-gibbz-arms-in-federal-court/
From: Soldier Systems