CRIMINALS or those behaving badly in the city centre be warned. They may hear a voice coming from the ether, warning them to watch their step. And no, its not film prankster Leon Schuster invading the capital city. They are allowed to intervene when there appears to be imminent danger. Unfortunately they are not allowed to victimise ordinary citizens, like those loitering and flirting with schoolgirls or those who are jaywalking — as tempting as it may be.