Daily Chinese Idiom Guessing Game
Hard to guard against or be on guard against; inevitable attacks or surprises that are hard to defend.
防防备；胜尽。形容防备不过来。
清·吴趼人《二十年目睹之怪现状》第四十七回这种小人，真是防不胜防。”
In the age of cyber attacks, data breaches are simply unavoidable—it's a case of being impossible to be always on guard.