Anonymous Bitcoin source which do not know who am i and what was the BTC source?

[postcd]

What are sources from which one can get Bitcoins while no one can prove for what/which purpose Bitcoins was sent and what was actual source of Bitcoins?

Im not looking for an anonymization service on which claims i have to relly. Im looking for something which do not logs any identifiable data about me from its nature.

Is there something like that and is there any country in which such a service is legal?