How often does it happen? You see something that is clearly out of place or violating a community rule. Next time, stop yourself as soon as you see it. Take a breath and release any annoyance or frustration that has arisen.
Now, make a story for it. A story that would justify the wrong or at least offer understandable and mitigating reasons for it. It doesn’t matter if the story is true or not, just that it allows you to apply compassion to the offender.
Next, put yourself in the offender’s shoes. Remember the compassion you are giving to yourself and how you would want someone to approach you to explain that you’ve offended.
If you feel the need to confront the offender, do so with this compassion in your heart. It may be they just need to be coached. Perhaps they were unaware of the rule and therefore didn’t realize they were breaking it. Perhaps they didn’t understand they were being offensive. Perhaps they are operating on a different belief system.
Regardless, approaching as a teacher, mentor or informer gets positive results far more often than preaching or demanding. And, giving someone the benefit of the doubt sometimes leads to a new understanding for yourself.