Why should we not talk bad about others behind them?

Question - Gurudev, why should we not talk bad about others behind them?

Gurudev Sri Sri - Often you talk behind people or make their fun and name it normal talk but this too creates a very harmful karma which comes to you in multiplied figures. It is very difficult to talk good always behind people, about them because it doesn't give you the certain feeling that you expect from the talks, but when you grow in knowledge and attain wisdom, you will only talk good about people behind them because then you realize its importance and effect on your karmic cycle.