Posting pictures of a Chaoboo, the man was caught by cyber patrolmen.
http://www.nintendoworldreport.com/news/24401
A fan who intended to "show everyone the characters that haven't been made public yet" might be in trouble (one could even say double trouble) after revealing six pictures of a Chaoboo and two other new pokémon online on September 1st, a full 17 days before they made their appearance in Black and White, the latest Japanese releases of the franchise.
While the source of the images couldn't be identified, the aforementioned pokémon were to be unveiled in the October issue of Shogakukan's Monthly CoroCoro Comic magazine, which shipped on September 15th.
Chikusei City's Makoto Sekuguchi, arrested on Tuesday for posting the pictures, was caught by the city's police while on "cyber patrol," and after consulting Shogakukan and the Association of Copyright for Computer Software (ACCS), they knew they had their man.
An investigation into how these images were obtained is ongoing.