Ethics is a code of thinking and behavior governed by a combination of personal, moral, legal, and social standards of what is right. Although the definition of "right" varies with situations and cultures, its meaning in the context of a community work involves many guiding principles with which most community activists and service providers would probably agree. Above all else, do no harm. Hippocrates put this in words over 2,000 years ago, and it's still Rule Number One.
You have volunteered to run a community violence-prevention program, working with kids who are gang members or gang hangers-on. The kids trust you, and sometimes tell you about some of their less-than-savory activities. The police also know you work with gang members and often ask you for information about kids. What are you obligated to tell them or to keep from them?
If you are actively striving to do "good," how far does that obligation take you? If there are issues affecting the community that have nothing to do directly with the one you're concerned with, do you nonetheless have an obligation to become involved? What if you don't really understand the whole situation, and your involvement may do much harm as good-do you still have an ethical obligation to support or become active on the right side? What if your support or activism endangers or compromises your community intervention?