Except their anti-cheat, Battleye, is invasive as all hell. Instead of just scanning the game folders for cheats (like all other games do) it'll scan your fucking entire hard drive and send full lines of data, filepaths, IP address, etc to BE's main server and stores it there.
When called out, BE devs will send warnings and even threaten action against those who call them out. This programmer decided to do some research into it and has released his findings. In so doing, a developer of BE contaced the programmer and threatened not only him, but others who have posted similar findings about BE. Even going so far as to call them "hack creators" and make him out to be a "criminal" "colluding" with other hackers, which is far from the truth.
BE's terms of service states BattlEye will never report any of Licensee's private data (documents, passwords, etc.) to other connected computers or to Licensor. BattlEye will not violate Licensee's privacy. But also says... BattlEye may scan the entire memory, and any game-related and system-related files and folders on harddisk and report results to the connected game server for the sole purpose of detecting cheats.