So the main problem is, that you agree to many points, battleye can use from your pc.
You agreed that they can scan you pc, connection and opened programs. So they need to workaround a whole bunch of things to get it running.
BattlEye may collect and process the following information from you:
IP address
Game identifiers (e.g. in-game name, account ID, etc.)
Hardware device information and identifiers (e.g. serial numbers)
Information about the running operating system
Information about game-related and operating-system-related files and memory
Information about running processes, drivers and other executable code
File names included in other information listed here, which might also contain your operating system user name
Btw, still damn happy about the Chods USB ! ?