Unconscionable conduct means conduct which is so rapacious that it goes against good conscience. Good conscience is an objective standard, ie: what would a reasonable person do. The classic case is when someone trusts you with the legal ownership of property asking that you hold it on their behalf. The courts of Equity have found that it would be unconscionable for you, under these circumstances, to use the property for your own benefit in breach of the trust. This finding is the whole basis of modern trust law. In relation to mortgages, lenders who are dealing with a vulnerable person, who loan know the loan will go into default, who set a very high interest rate, are behaving unconscionably.