That is the problem as individuals we do feel powerless, but if there are, say, a dozen people in the street who also feel powerless then the answer is to collectively cooperate to deal with the issue, ie organise, but at the same time resist the temptation to engage in mob rule. Use safty in numbers to voice that fact that their behaviour is intimidatory and won't be tolerate, and if necessary make collective disposition to relvant authroties - eg local CSO,community safety teams.