In this context, “instigators” are those who have something to gain by propagating social evils. They make engaging in these behaviors possible. However, there is some question surrounding who is most to blame: the “instigators” for provided the tools of vice, or those who take advantage of what “instigators” have to offer? When Mill mentions “breaches of the peace” as justification for penalizing establishments that, for example, provide alcohol, he means if any crimes are committed there (physical fights, for example).