Legal aspects of machimina
The big issue in Second Life is copyright. The creators of Second Life, Linden Lab, assign intellectual property rights in the avatars (characters) and the objects that individuals create to the Second Life users who create them. This means that you would need to get permission from the creators of any avatars or scenes that you film in Second Life, in order to avoid breaching copyright.
Generally Linden Lab does not give permission for anyone to film in Second Life because they do not own the content (the copyright in the avatars and scenes) but they do however liken filming in Second Life to filming in New York, where generic street scenes and landscapes can be considered “fair use”.
from: Machinima the legal way - a post by Mixin Pixel. Read more...