noun
stalker
A person who persistently follows, watches, or harasses another person, often in a romantic or obsessive context. Commonly used in legal and news contexts.
彼女はストーカーに悩まされている。
She is being troubled by a stalker.
ストーカー規制法が施行された。
The anti-stalking law was enacted.
A more general Japanese term for following someone persistently, not necessarily with the same criminal or obsessive nuance as ストーカー.
Borrowed from English 'stalker'.