People differ in their levels of trust, social values, and personal tastes. Some will be
rallied by their optimism, while some may hesitate, perhaps because of the overly optimistic
propaganda of previous campaigns. Underlying this difference is uncertainty over
the effectiveness of the effort. People will not join unless they are assured some probability
of success, especially given the risks of participation. Safety in numbers is especially
important when considering levels of distrust between many community members and
police, and when considering the risks of collective action, such as retaliation by drug
dealers (Grine, 1998).