Is it a common thing in the wild to attack?

Have you ever heard about orcas attacking people in the wild, so why has there been some many incidents recorded in captivity? Isn't it obvious why these animals in captivity have lashed out before and attacked. They are prisoner of profit, my meaning behind it they are taken from the wild and put into a isolated place where they have to perform for the rest of their life's. These animals become bored and their frustration and anxiety start building up which makes them start acting up. Anyone kept in captivity for so long and being deprived of their own life would become insane and aggressive. You can't expect theses animals to not express what they feel, they are living things too and have to express themselves some how.