It's obviously done as a protest and to get some publicity. I don't think that they honestly believe that they will meet their goal. There actually are laws against the kind of domination of media that Rupert Murdoch has. Yet when you have the kind of power that he has, governments bend to his will and give him special exemptions.
Perhaps as you imply this is to let a few on the side of Murdoch cry foul so there is a precedent set against their own side. That hypothesis is either evidence of genius or idiocy. All possible puns intended.
