body: In country A, it's illegal to say something to a person (it's considered a severe insult that is punished with jail)
  
  
  User 1 is using Twitter in country B, where such law doesnt exist, and he is a citizen of country A, and he says something about another user 2 (in country A) where such thing said it's illegal . 
  
  
  Twitter is hosted in country C.
  
  
  Is User 1 committing a crime? Or the law from country A doesnt apply to him because he's in another country and the service he is using is in a third country?
  
  
  BTW, I couldnt come up with a better title. If you can come up with a more descriptive title, please edit it. 
  
  
  
title: How do you laws apply through internet regarding the different countries?