stalker

S.T.A.L.K.E.R. is a series of first-person shooter survival horror video games developed by Ukrainian video game developer GSC Game World for Microsoft Windows. Based very loosely on the novel Roadside Picnic and the 1979 film adaptation Stalker, the games are set in the area surrounding the Chernobyl accident site, called "The Zone", in an alternative reality where a second explosion occurs at the Chernobyl Nuclear Power Plant some time after the first and causes strange changes in the area around it.

Stalking is unwanted or obsessive attention by an individual or group toward another person. Stalking behaviors are related to harassment and intimidation and may include following the victim in person or monitoring them. The word stalking is used, with some differing meanings, in psychology and psychiatry and also in some legal jurisdictions as a term for a criminal offense.