Em. Thomas Paine, James Madison, Alexander Hamilton, John Jay, Benjamin Franklin, John Marshall, John Locke, Immanuel Kant, David Hume, Baruch Spinoza, René Descartes and many, many more wrote anonymously.
Some wrote anonymously because they wanted the words to speak for themselves, such as Madison, Hamilton and Jay writing the Federalist Papers.
Some did it because they thought their name might detract from the message - such as Franklin's writings when he was a teenager.
And some others did it to avoid consequences for their opinion - such as when Thomas Paine penned the case for American independence - literally treason. Even Paine's publisher, Benjamin Rush, remained anonymous!
The idea that free speech without responsibility wasn't a consideration seems contradicted by how utterly pervasive it was by classical liberal philosophers and founding fathers and how influential those writings were to the founding of the country and the creation and passage of the first amendment.
