"The law of karma is not a justice and retribution system,
so anyone who has had much suffering in this life
is not a victim of 'bad karma'"
As we travel through this life, we must take responsibility for our actions. Karma states this quite clearly, that there is a reaction to whatever we do - an outcome. It is classic cause and effect, illustrated in the saying "what goes around, comes around". Some people, however, believe that whatever happens to them is a result of the universe ganging up on them, and that they are somehow being punished, or indeed that this is unjust.
Karma is long-term, and the "Golden Rule" principle of "do unto others as you would have them do to you" is fundamental in every walk of life. In fact, it is not the action or deed which attracts the karma. Rather, it is the emotional state that led to the action which does the damage. "Behaviour Breeds Behaviour", as I am fond of saying in Customer Service courses - people react as they find you. So for example, trolls in E2 find themselves treated badly because people react to what they say. As a consequence of this, they feel unloved, and lash out. The cycle begins anew.
The reverse is also true - I have found many people here who react postively to what I write, that I /msg them with corrections, and good karma as a result.
Good things come to those who wait - but bad things are often of your own doing.