"To find fault with others and talk about it is a sinister act in itself; it is also an indication of an impure mind. Your mind will become more composed and unfettered if you get rid of the habit of differentiating pleasant circumstances from the bad. Therefore, keep it to yourself when you see anything immoral or anyone breaching the Dharma. Do not expose them, nor feel any aversion. 'With your mind in a pure state, you will be free of vexations.' This also indicates the potency of your practice." (1)
The objective in our practice, in our cultivation, is to maintain the mind that is not swayed from its naturally calm, clear state. Ideally, when we see someone doing something wrong, we view the act as purely as a mirror reflects what is in front of it. When we are not yet at this point, we will be tempted to speak of what we have seen to others. But this is a discriminatory thought, a wandering thought that does not advance us in our practice of helping others.
Speaking of the immoral, unethical, or just unkind actions of others will agitate us and cause us to be annoyed or perhaps frustrated. Hardly the state of a happy person at ease with the world.
We need to get out of the habit of gossiping and carelessly speaking of the actions of others. See it, and let it pass.
(1) Analects of Master Kuang-ch’in