I certainly don't fault people for hiding behind a screen name or pen name out of necessity, due to safety concerns or work-related issues.
But when they abuse that practice by being vindictive WHILE they hide behind that screen name or pen name -- they're pretty much obliterating their own credibility.
If someone is going to be vindictive to me online, they should have the guts to do it using their REAL NAME & IDENTITY.
Post-Disclaimer: By "vindictive," I'm referring to provocateurs who flaunt their bigotry and animosity under some pre-scripted "justification." I'm not referring to anonymous contributors who simply disagree respectfully.