Do not allow them to enter

The Holy Prophet of Islam (peace be upon him and his progeny) said:
“أَرْبَعٌ لا يَدْخُلُ بَيْتاً وَاحِدَةٌ مِنْها إلاّ خَرِبَ وَ لَمْ يَعْمُرْ بِالْبَرَكَةِ: الخِيانَةُ و السَّرِقَهُ وَ شُرْبُ الخَمْرِ و الزّنا”

Translation
If any one of the following four things enters a home it will ruin the home and divine blessing does not re-establish it: treachery, larceny, drinking, adultery1

Brief Description
This is true for homes as well as for the entire society.
When treachery penetrates into a society, the spirit of confidence disappears.
When larceny, in its different forms, appears therein, peace will not be found anymore.
When alcohol drinking becomes popular among people, they will have weak thoughts, disabled children and useless youth.
Lastly, when they are stained with adultery, the foundation of families will be weakened and their next generation will be mischievous.[divider]
•    1. from Nahjul Fasahah,