I have told some practitioners that extreme thoughts are caused by thought-karma, but many practitioners now consider all their bad thoughts in everyday life to be thought-karma. This is incorrect. What is there for you to cultivate if you no longer have any bad thoughts?! If you are so pure, aren't you already a Buddha? This is a wrong understanding. Only when your mind violently reflects filthy thoughts, or curses Teacher, Dafa, other people, etc., and you cannot get rid of them or suppress them, would this be thought-karma. But there is also some weak thought-karma, though it is different from regular thoughts or ideas. You must be clear about this.