When it comes to Cursing, Jinxing, Blasting, Tudding, Hexing etc. A lot of people have different views on the matter, some believe in a kind of 'karmic justice' where what you do will come back to you, some do not.
Generally though, when it comes to Baneful Magic, you must take responsiblity for your actions, once cast, a Curse cause interfere in many ways with a persons life, you must be able to live with yourself after the cast, because you will become part of the equation of why their life is spiralling out of control.
Do as you want to though, everyone has different views on the subject. Some people stand outright against it, some are advocates for it.