I was bullied as a kid. Had low self-esteem, little confidence, was very sensitive, easily intimidated. Some of these issues still surface from time-to-time.
However, it's being on DBs over the years that helped me develop a thick skin. Oh the insults I'd get sometimes! I used to shake when reading a hateful reply! Now I usually take insults with a large pinch of salt - as the last recourse of a person clean out of cogent arguments.
There has to be good judgment when pushing an argument or question. When does pressing for an answer become bullying or stalking? When is the right time to let it go and allow the opponent to save face or have a more gracious exit from the discussion? It's sometimes difficult to gauge when you smell blood and want to follow through to the kill.
I think name-calling can be funny if done judiciously, and provide light relief in a dull or stale discussion, as long as it done more slapstick-style than with malice. And the giver should be willing to take a few themselves, hey? Generally, the Golden Rule should be the ethic.
On the other hand, arrogant, dense, stuffed-shirts are prime targets and deserve all they get IMHO (a few names readily come to mind - thinking in line with Bungi Bill's post #478).
My $0.02.