In journalism, anonymity is a confounding thing.

It can be a reporter’s best friend or his worst enemy. Anonymity brought us Watergate. Anonymity brought me some otherwise impossible-to-attain insights into Barry Bonds and Roger Clemens for two of my books. I’ve promised anonymity dozens of times throughout my career, sometimes with a, “This is just for background” assurance, other times with a source saying, “I’ll talk, but you can’t use my name.”

The key to anonymity is trust, to two degrees. First, a journalist must trust—without question—that his anonymous source is telling the truth and worthy of anonymity. That’s why magazines like People and Life & Style irk the hell out of me. They use anonymous sources all the time, but it’s always, “‘Britney was angry, and she stormed out cursing at everyone. She seemed to be in a really bad place in her life,’ said a neighboring diner.” During my Bonds book, for example, I had to know—without question—that any anonymous insights were based on more than second- or third-hand observations. It had to be, “I was there—directly involved” or “I talked with Barry about this 100 times.”

Second, the journalist has to be trusted by his readers. If Tom Verducci or Howard Bryant cite an anonymous source, I have no doubt in the legitimacy. They’ve earned that right with their customers. If Kitty Kelly does so, well, I’m suspicious.

I suppose the one thing about anonymity that bothers me most is the cowardice. I understand not wanting to lose a job, or fearing how a stated opinion might impact, oh a family member. But today, more than ever, anonymity is an encouraged, accepted form of stating one’s opinion. I’ve certainly had my moments—no question about it. But by and large, I do believe that if you have something to say, put your name behind it (hence, this blog). Thanks to the invent of chat rooms, message boards, blog postings, etc, people can anonymously slam others without any risk of backlash. An anonymous person can thrash someone to pieces, and what’s the comeback? How can you pummel the invisible?

It’s funny—when I receive especially harsh e-mails to this site, they are almost always accompanied by fake names and e-mails. I write a note back, and the address doesn’t exist.