legal vs illegal

Mahendra D. Jain vs. ITO (Bombay High Court)

Where the assessee is carrying on an illegal activity which is treated
as a business, any loss arising in such business as a result of
confiscation by the authorities is an allowable loss. However, where
the assessee is carrying on a lawful business, any loss arising as a
result of infraction of the law is not allowable... .......