I found some interesting resources about this: http://en.wikipedia.org/wiki/Kony_2012#Criticism_and_responses
My first reaction is that it probably did happen that Kony is a war criminal, but it seems unlikely that there will be cooperation in capturing him to the extent that the producers would like. This part of the world is a mess.
I don't think it's a scam, but I do think that it's a somewhat narrow view of the situation that is intended to promote the point of view of the person and organization that has put the documentary out. Kony and the LRA were without question brutal in what they did to try to win their conflict. However, it is clearly oversimplified and it reflects something that happened in the past, not something that is a major problem at the moment.
What’s happening with Kony and all is absolutely horrible and really quite terrifying if you think about it. Little boys and girls are being torn away from their families and lives, and start to live a life filled with hatred and horror. Boys are used as child soldiers and used to kill, and they don’t escape because they have nothing to go back to because Kony made them kill their parents or siblings. The girls are used as sex slaves and live a horrible life. It’s absolutely horrible what’s going on with Kony and I really hope Kony gets arrested soon, because what he’s done to children is not natural. There are people who are devoting their lives to make sure Kony gets caught, even at the cost of madness, so it’s only right for us to help get Kony caught. Check out the Kony 2012 nmbr 2.
I agree with Post 3, the continent of Africa is a mess. Governments there are corrupt and unstable, and the element of greed is common among governments. I believe Joseph Kony exists, but I doubt he has done the harm to the extent inwhich Invisible Children claim he has. Advertising is usually exaggerated, so keep that in mind!