Battlefield Friends made a contest on a BF4 easter egg that no one had found yet:

https://m.youtube.com/watch?v=_myHr9wNF5o

The secret was then later revealed here:

https://m.youtube.com/watch?v=TieCogcx4zM

It's well worthwhile checking out if you like Battlefield Friends animations and sense of humor! One of the guys in the BFF crew is Newground's JonnyEthco: 

http://jonnyethco.newgrounds.com

Check out his shit too, you'll hear that some of the guys from BFF are in his movies too! These guys are freakin awesome, be sure to check their stuffff out (especially JonnyEthco's stuff here on NG;).