Dr Mahathir: Why would you call a thief 'bossku'?

Prime Minister Dr Mahathir Mohamad took a swipe at Najib Abdul Razak and the supporters that call him 'bossku' (my boss).He said the word "boss" is the term that was used by African slaves to refer to their Western masters."So when we call him 'bossku', it means you are a slave to the boss."We have already achieved Merdeka (independence), but you still want to be slaves?" Mahathir said to cheers from the 3,000 strong audience on Thursday.