Copy Right Laws

I never know that even when putting in power point pictures you could be braking the law. I see that the right full owner deserves their credit but some of it seem a bit extreme. I know if you copy past an story or wed text, that's wrong, but I never know that it was that strict with pictures. At in the end of the day we are just students and know one really thinks you took, draw, or created that picture. They may ask were you got that picture and its always easy to answer that.