Learn in the textbookClassifying Threats — Human Wrongdoing and Accidents
DefinitionShoulder surfing (盗み見) is obtaining information improperly by looking at someone's screen, papers or what they are typing, without that person noticing.
ExplanationThe trick of peeking at a screen or someone's hands from behind is also called a shoulder hack (shoulder hacking). It works with nothing more than human eyes and needs no special tools.
AnalogyIt is like the person queuing behind you at an ATM quietly watching your hand as you enter your PIN.
Memory hookIn English it is called shoulder surfing. Picture someone looking at a screen over your shoulder.