For a few fleeting weeks, anonymity meant freedom for J.K. Rowling.

A London law firm apologized late last week for exposing Rowling’s secret pseudonym — that is, Robert Galbraith, the supposed first-time author of the critically acclaimed but modestly-selling detective novel, The Cuckoo’s Calling.

Soon after the secret was leaked, The Cuckoo’s Calling skyrocketed to the top of the Amazon best-seller list, with first edition copies going for over $1,000 a pop. Great news for her publisher, no doubt, but Rowling was not pleased.

She who must not be named
So what exactly is Rowling griping about? For starters, a respected law firm leaked her identity in a major breach of confidentiality. But more than losing a sense of privacy or anonymity, Rowling lost her ability to experiment and play without the pressure of expectation. As she notes in the FAQ section of Robert Galbraith’s author website, her pseudonym wasn’t a marketing ploy, but rather a desire to fly under the radar: “If sales were what mattered to me most, I would have written under my own name from the start, and with the greatest fanfare.”

Rowling also notes that eventually, things may have gotten complicated with requests for interviews with Galbraith coming in — but she hoped to reveal her pseudonym on her own terms, if it came to that. For people wondering why in Voldemort’s name Rowling wouldn’t publish under her own name in the first place, just consider the very public lukewarm reviews she received for The Casual Vacancy, her first work following the Harry Potter series. It was impossible for her to dabble in a new genre without constantly hearing from fans or reviewers that it wasn’t as masterful or immersive as Harry Potter. A good problem to have, in a way. But I understand Rowling’s desire to have a secret, just for a little while.

The purpose of pen names
These days, it feels like there are so few secrets.  That’s why we get such glee out of mysteries like the anonymous writer behind the hilarious Ruth Bourdain Twitter account, which satirized food writing with particular relish (excuse the pun). In the age of personal branding and over-sharing, it was hard to imagine someone not taking credit for creating something so popular. I guess sometimes, a pen name is about the sheer joy of mystery.

Of course, there’s the dark side to anonymity as well. Anonymity on the Web makes it possible for people to share questionable and sometimes downright harmful ideas without having to be accountable for the consequences of their actions. To be sure, there’s power and bravery in putting your name on a piece of writing that’s open to ridicule, debate, or misinterpretation by anyone in the world with access to the Internet. But not everyone’s lucky enough to be granted freedom of expression, and sometimes pseudonyms serve a real purpose. Here’s a look at why a few famous writers adopted their pen names:

George Sand (a.k.a. Amantine Dupin)
George Sand was a prolific French author, writing in the mid-1800s with contemporaries like Victor Hugo and Honore de Balzac. As a woman, she struggled to find publishers who would take her seriously — which is eventually how she stumbled on the nom de plume of George Sand (a lover named Jules Sandeau supposedly helped her settle on the name).

Mark Twain (a.k.a. Samuel Clemens)
Samuel Clemens was America’s first celebrity author, but one of his earliest jobs was piloting riverboats.  “Mark Twain” was a term referring to the second mark on a line that showed where the Mississippi was two fathoms deep. It became Clemens’ pen name when he became a reporter — a common practice, especially to protect crime reporters.

Dr. Seuss (a.k.a. Theodore Geisel)
Theodore Geisel adopted the pen name Seuss, his mother’s maiden name, after he was banned from writing for Dartmouth’s humor magazine (he got caught drinking with friends in his dorm room). He upgraded himself to Dr. Seuss after graduation. A playful pen name bolstered the sense of whimsy he created in his books (true for Lemony Snicket, too).

Robin Hobb/Megan Lindholm (a.k.a. Margaret Astrid Lindholm Ogden)
Hobb, a best-selling science fiction author, first published her work under the name Megan Lindholm. She was originally going to publish as M. Lindholm, when an editor told her it was important for women writers in science fiction to “declare themselves.” Eager to explore new styles and perspectives, she later took on the pen name Robin Hobb.

Like Rowling, she likely realized that maintaining two successful author personas as just one real person wasn’t going to be easy — and she eventually revealed herself as the writer behind both identities. Today, she continues to publish under both names.

The lesson for the rest of us writers? If you’re in a rut or paralyzed by a vicious attack of “what ifs” (What if they hate it? What if it’s no good?) consider writing under a different name, even if it’s just on your blog — you might find a voice you never knew you had.