"newcomer, new person to an existing situation," by 1969, from new with diminutive or derogatory suffix. Perhaps originally U.S. military slang. Cf. noob. Middle English had newing "a new thing" (early 15c.); new was used as a noun meaning "naval cadet during first training on a ship" (1909); and newie "new thing" is recorded from 1947.
A person new to computers and computer networks; computer neophyte: You'd copy it because you didn't want to seem like a newbie (read: clueless computer rookie)/ Newbies sometimes get flamed just because they are new (1990s+ Computer)