Years of work on comprehensive, community-based initiatives are making it clear how important it is for citizens to grasp the full complexity of certain community issues. It may be possible to put a stop to littering with a few people, organizations, and actions in a short period of time. To take on gang violence, the sex trade, poverty, or the trafficking of drugs or cigarettes, however, citizens must work from a very different set of assumptions. These problems are so complex as to be best described as "wicked."
Wicked problems have six major characteristics. They are difficult to define with precision, and change dramatically in size and composition from the perspective of one stakeholder to another. Their root causes cut across such neat boundaries as "social," "economic," and "political," and will not likely respond to strategies with a narrow focus. They involve very diverse groups of people who nevertheless must find some meaningful common ground in order to work together.
Wicked problems don't stay still; they change over time in response to different events and circumstances - including the measures taken to address them! While the same problem may appear to beset two communities, the same measures cannot be applied in the same way in both places. The problem is unique to each.
Finally, while you may be able to keep them in check, you are unlikely ever to solve wicked problems. Citizens that wish to "do something about them" must get ready for a long, messy endeavour that progresses at best in fits and starts and that they personally will not see to its conclusion. When you're dealing with wicked problems, that's what winning looks like.