IMHO the internet is a lawless place.

I am sorry and I dont want to offend the OP but if anyone here is arrested today (relating to anything bitcoin) then, unless you happen to live in the same jurisdiction as OP, he will not be defending you.

The following however is true all over the world:

1) Can you be arrested for your involvement with Bitcoin? {yes} You can be arrested for anything at any time. People get arrested unlawfully all the time.
2) Will you be arrested for your involvement with Botcoin? {probably not} The fact of the matter is that it is very unlikely that any government will go after "the man in the street".
3) If arrested will I go to jail? {probably not} Think about it: the presiding officer {judge} would have to be persuaded that you did something illegal {many jurisdictions this will not be true} and that you knew that you were committing a crime {this may vary from jurisdiction} and that the punishment that fits the crime is to put you in jail. - hmm NO.
4) Can I sue member X because of ....... {yes but do you really want to?} We have to find him and sue him where he lives and when we get to court we have to persuade the presiding officer which legal system was applicable and what the principles are.

Practically speaking I dont believe that the courts will assist us in regulating bitcoin. I also dont believe that if the governments of the world whished to attack bitoin that it would be by arresting the people that use it.