I agree that people who do this kind of thing are very insecure, and feel they have to put others down in order to build themselves up. These kind of people never make good friends. I've worked with people like that myself (I think we all have at one time or another) and they are toxic, dominating, and the only way they can feel good about themselves is by cutting others down. They will usually pick only on people they sense are "weak," and by that I mean people who won't stand up to them, are too polite to get in their faces about it, or shy people. I got picked on one place I worked, by one very nasty, obviously unhappy woman, and even though it took me 5 years I finally quit, and have never been happier!