1. What does it mean?
눈팅 means following a forum, chat, or comment section while remaining a quiet observer. 눈팅하다 describes the activity, and 눈팅만 한다 emphasizes that somebody mainly reads rather than contributes.
Also written or said as 눈팅하다, 눈팅족, nunting
2. The nuance
It is closer to 'lurking' than spying. A newcomer may 눈팅 to learn a community's tone before posting. The word does not by itself imply stalking, access to private information, or disapproval.
3. Examples
“처음 가입한 모임이라 며칠은 눈팅하면서 분위기를 봤어.”
I'd just joined the group, so I lurked for a few days to get a feel for it.
“늘 눈팅만 하다가 이번 책 이야기가 나와서 댓글을 썼어.”
I usually only read along, but I commented when this book came up.
Sources
National Institute of Korean Language
References support the meaning and usage. Example sentences are written for NoCapWiki.