Question: Why do some people appear to seek out the vulnerable, and then attack them? 

Answer: It's usually low self esteem,anger ie :- hurt people hurt people..and sh*t rolls downhill.. Putting people down in one way or another makes the bully/coward feel good about him/herself.. They want to seem to be in control to feel important.. They're usually insecure.. they're afraid to let you see the real them because that's all they've got and it might not be enough for you so they try to show some sort of domination/power trait.. In short it makes them feel better !
This question from the Yahoo Q&A forum is categorized in the topic: Business & Finance