Eiichiro Oda, Mangaka of One Piece received around 100 text messages to his mobile phone from September 2007 to December all with the message "Die. Die".
The culprit was apparently a previous assistant drawer's wife who held a grudge for her husband getting fired.
She was arrested on the 7th of this month.
Source: Yahoo News Japan
I kinda understand how she could be a bit upset. I mean, I'm sure she bragged to her friends about how her husband was working on the greatest manga in Jump but... To then go and send death threats? >.> She's now my own personal enemy >.>...