Sure, absolutely.
As do many academics, I write and I publish. This book is one example, but there are a number of others.
I'm practising what I'm preaching in the sense that the approach I take is to have this book available in print form and also to have it available free to download through a Creative Commons licence. Our publisher--a mainstream legal publisher, Irwin Law--has found that it's actually a viable commercial model to have the book available for purchase as well as available for free download. They find they actually are in a position to sell more books because they're adopting that open model, and that would be true, I think, for a growing number of people.
What we're talking about is a range of different models. Some of them can be closed and some of them can be open. All of them, at the end of the day, still respect copyright, and certainly I do with some of the choices that I make with my own writing.