Legalizing a Practice due to it becoming Common

Hazrat Moulana Ashraf Ali Thanwi (rahmatullahi ‘alaih) once mentioned:

Once, a person wrote to me that nowadays it has become a norm in society for people to illegally travel by train without purchasing a train ticket. Hence, there is a need that concession be granted by the Ulama for this situation.

I replied that through an impermissible practice becoming common among people, how can that be a reason to declare that practice as permissible? Hazrat Thanwi (Rahmatullahi Alaihi) then mentioned that unfortunately the public feel that whenever they are involved in any impermissible practice, then they expect the Ulama to find some loophole to legalize that practice and thereby remove it from the list of impermissible practices. (Malfoozaat Hakeemul Ummat 1/43)

Source: Ihyaauddeen.co.za