I think it's good to understand all types of people, their nature etc. Such information would sometimes protect us from swindling and so on by other people. Of course, becasue we know that other person is bad, shrewd and what not, we cannot kill that person. All we can do is protect ourselves from them. Therefore, sharing tips or info on other person is always good thing, however cannot always genralize it, should not use foul language etc.