From ancient times, people have been scared of the curses of witches and wizards, and often many times such unfortunate incidents of disease and sickness of people and livestock was blamed on the local sorcerer who felt the need to execute a curse on the surrounding folk.
In recent times of course, apart from superstitious peoples, this phenomena has been relegated to the past. There are of course many who practice magick, who do still curse, usually for revenge aimed at a target they feel has wronged them in some way. I'm not really interested in discussing the rights, wrongs or morals of this, as it's all been said before (karma, the three-fold law etc) and I don't see myself as some kind of magickal policeman.
My take on cursing has mainly always been this - I just can't be bothered! So someone has really gone out of their way to be a pain to me, even verbally taunted me. I just tend to walk away, I can't give such people any of my precious time to even look back, let alone go out of my way to perform some magick to get back at them. Why would I? I have a thousand and one other magickal projects to work on, to benefit myself and people I care about, so I'm not about to waste valuable magickal energy on such idiots as these. Normally they are like the adult version of the school bully anyway, they do it to others, because they are unhappy with themselves. I've also found that if they see they aren't getting to you anyway, they give up and move on to a new target.
There are some exceptions where I would curse, or at least use combat type magick. Normally this would include direct physical threats either to myself or loved ones, this would form a "preemptive strike" to put them out of action before they had chance to follow through.
A time to kill, and a time to heal; a time to break down, and a time to build up;