Player ejecting mass very fast with "macro"
Macro can refer to macro split (splitting in 16 pieces), however, in the context of the mobile Agar.io app it refers to a manipulation that allows players to eject a lot of mass in a very short time. This is considered a cheat and many players don't like it, because it can cause lag and and allows super fast self-feeding. Technically it works by another app - running in the background - sending lots of simulated touch events to the Agar.io app, with a high frequency.
Countermeasures
The use of macro, as feeding is currently implemented, cannot be prevented. This is because inputs are simulated by third party apps. There is no way for Miniclip to detect other apps and take action against macro users on that basis.
Mobile Agar probably uses a classic client-server architecture and the game world is not calculated in the app but on a server. The app only takes input and forwards it to the server, and receives information from the server with which it renders the game. Therefore the frequency with which a player can feed per second could be limited on the server-side, for example, to 4 times per second. This should be trivial to implement and would be an effective protection against mass spam. This mechanism is already used on the servers for the PC version and it works fine there.