What is the origin of the idiom "get in one's face" and when to use it?

The origin of the phrase "get in one's face" can be traced to American English slang, particularly in the late 20th century. The phrase draws upon the literal idea of someone invading or encroaching upon another person's personal space, bringing their face or presence uncomfortably close. The phrase can also be used metaphorically to describe actions or behaviors that are intrusive, overwhelming, or excessively close in proximity, even if not in a physical sense.