Some users manually replace files in the \main folder of the game directory with English .iwd or .ff files.
Is downloading a language patch piracy?
To enforce this, publishers use . The theory is: if a Russian player buys a cheap key, they will only get Russian audio/text. An American player who buys that cheap key would find the game unplayable in English, thus disincentivizing the purchase. Call Of Duty Infinite Warfare English Language Patch