[jonnathanson]

"With periodicals, though, there usually is a contract with writers where rights are assigned to the publisher. Maybe the copyright, maybe just a license. There's usually something along those lines."

Publications usually allow the writer to retain IP ownership, but with an exclusive license granted to the publication for a certain period of time. For instance, "Joe Writer agrees to license to PublicationMagazine the exclusive worldwide rights to the work for a period of N days." Depending on the contract, many publications will also want the right to sublicense or syndicate the work during their license period, but will compensate the writer X% of syndication revenues.

I've never written for HuffPo, and I have no idea how their process works. I do, however, think it's a raw deal for any writer to contribute for free on an ongoing basis to a successful, for-profit publication. Not that there's anything illegal or immoral about that, per se. It's just that the writer is selling his time and product very short. Plenty of successful, respectable publications will pay a writer for his work. It won't be much; journalism isn't exactly renowned as a path to material riches. But at least it'll be something.