"He who conceals others faults,Allah conceals his/her faults" appears to be pretty straight forward statement but if you think about it it goes a little more deeper than that.
Let me explain, you see someone doing something you consider wrong,let us take a simple example, you see a friend smoking and you go and talk about it with your other friends and you talk about him and smoking is bad etc and you tell your self "Its not bad to talk badly about something bad".
Now let me explain what is really happening, first of all if you have anything negative to say you can go and tell that smoking friend but you have no 'right' to talk about him with your friends because then it becomes 'backbiting' and a lot of extra lies become mixed with the truth.secondly you are not only talking about the bad act but also the person you associated with the bad act, thirdly you revealed his mistake or act to a number of people who might not conceal it.So he did 'one' bad thing you did 'three.who is better?
Dear friends this was a simple example and a lot of you might be smokers but the point i am trying to make is that,this kind of behavior is very prevalent in our society,this gossiping and backbiting,you must have seen this behavior against 'girls and boys sitting together', just random girls, their appearance, drug addicts and almost about everything negative a person can do,another person is interested in spreading.Why are we so interested in other people's mistakes? ( Because of our own low self esteem ).
Learn to conceal others mistakes, don't talk about and spread them and Allah will conceal your mistakes.Learn to identify when you are 'gossiping', when you are 'backbiting' these vile acts have become our habits.If you want to stop an act 'go and stop it' but if you think, talking about it with others and talking negatively for that matter is doing a good thing, then you are sadly mistaken.
if you have any questions/additions/suggestions don't hesitate to comment, i 'will' reply.