I'm not sure if 'real altruism' = altruism as we describe it can exist.
Religious people could do it so they'd get into heaven, people could do it because altruism is a form of surviving in group (Prisoners dilemma).
We could do it to make ourselves feel better.
If I take all these things into account, I'm not sure if I can still believe there's a form of altruism where people act good ONLY because of the sake of others.
So, my conclusion:
1) My definition of altruism is faulty
OR: 2) There is no true altruism.