contributions to a wiki

• the original authors own the copyright, not the wiki they're submitted to, as long as:
  1. the work isn't done as a "work made for hire"
  2. the copyright owners haven't explicitely agreed to a transfer of copyright ownership
• only the copyright owner can sue for infringement (see Silvers v. Sony and others)
• when multiple people edit the same article, how is the copyright shared?
  • either they've created a joint work (the copyright to the work is owned by them jointly and equally)
    • any of the authors by themselves can sue for copyright infringement
    • any of the authors by themselves can distribute it under the license they choose
  • or the later contributors are creating derivative works of the earlier works
    • ALL authors have to agree before the work can be relicensed
  • they are NOT producing a collective work, because a collective work is one that's made out of multiple independent works owned by different people (i.e. it's possible to extract an independent work and have it stand on its own). A single article usually is not made out of multiple independent works; the determining factor that courts use is whether the authors intended the works to be independent or not.