V. Every one should abjure such men, and give all the information they possess about them to the authorities
And so, dearly beloved, renounce all friendship with these men who are utterly abominable and pestilential, and whom disturbances in other districts have brought in great numbers to the city: and you women especially refrain from acquaintance and intercourse with such men, lest while your ears are charmed unawares by their fabulous stories, you fall into the devil's noose, who, knowing that he seduced the first man by the woman's mouth, and drove all men from the bliss of paradise through feminine credulity, still lies in watch for your sex with more confident craft that he may rob both of their faith and of their modesty those whom he has been able to ensnare by the servants of his falseness.
This, too, dearly beloved, I entreat and admonish you loyally to inform us, if any of you know where they dwell, where they teach, whose houses they frequent, and in whose company they take rest: because it is of little avail to any one that through the Holy Ghost's protection he is not caught by them himself, if he takes no action when he knows that others are being caught. Against common enemies for the common safety all alike should exercise the same vigilance lest from one member's wound other members also be injured, and they that think such men should not be given up, in Christ's judgment be found guilty for their silence even though they are not contaminated by their approval.
Source: Sermons (New Advent)