I will explain why you all got dc ingame and what it couse...
DC hacker is using channel overload or server overload.
Each pc sends a data packages to server to communicate with database (registers your ip address). Any connection for client has flow of data (quantity of packages in one connection time to not overload server).
Basically it means... He targets on you and tell the program to overload flow of data... Idea is like when you play fps online games you can see your ping. When your ping is to high - you got dc. But for this problem it's on internet data flow rate. If you are overloading the internet traffic it may cause to malfunction server but server main function is to make sure that server connection to all is stable - so you got disconnected from server.
Life guard etc. this threat doesn't inspects as threat so he pass trough as usual thing.