There is no conspiracy. You don't need a conspiracy when people with identical interests come together. When a crowd jumps up and screams when their team in the arena scores, there is no secret ringleader telling them when to jump and what to scream - crowd dynamics and a shared interest nicely takes care of all of that without any organisation or collusion.
Same with the banks-plundering-countries scenario. I don't think they meet somewhere to discuss the plan. But the financial markets sufficiently replace any such communication by clearly outlining where to go and where to leave. Everyone moving in the same direction chasing profits is functionally identical to everyone moving in the same direction because they agreed to do so in a secret meeting.
And, actually, the banksters are doing both. The LIBOR scandal made it clear that there in fact are criminal conspiracies in this whole mess. I still don't believe there's a big conspiracy, simply because it's not needed.