This girl was Dutch, it was on the news in the Netherlands The girl and her mom went to the police to turn her in. I don't know if she was punished or not, but I think she learned her lesson. Source: http://nieuws.nl/algemeen/20140414/Meisje-14-aangehouden-na-dreigtweet/
You'll have to put it in Google Translate though, since it's in Dutch.
You'll have to put it in Google Translate though, since it's in Dutch.