In my opinion one of the most interesting ones ive heard. So basically in 2013 there was this 4cucker on the /sp/ board named UTV. Then, there was this absurdly autistic guy called "the archiver". The archiver was his stalker, and he loved and was extremely obssesed with this UTV guy. He went on to write a
97 page document consisting of his posts, his threads, songs dedicated to him, psychological Rorschach tests, tracking his daily schedule, really weird fanfiction, hints of wanting to meetup with him irl, poems, etc etc. Once the archiver posted the entire document on 4cuck, the entire board was utterly stunned.
UTV himself was shocked by the level of stalking, and then went on to reply with a single question mark, before never being seen again on the board. This event is said to have killed namefagging on /sp/, as many namefags became anonymous.
However, thats not even the end of the story. The stalker’s parents eventually
found out about his obsessive stalking and his 97 page document which lead to his internet activities being ceased.
https://knowyourmeme.com/memes/events/the-philmarilion