Some SEO practices can be good or bad, depending on why and how they’re used. There are, however, some practices that are just bad. Some practices may be caused by inexperience. Other practices, like hiding text or buying links, can be someone’s attempt to get better rankings with the thought it shouldn’t be wrong because they aren’t hurting anyone else. Then there are practices that are immoral and sometimes just plain illegal. Oh, and, may the force be with you!