It'd be cool to limit posting by only public resources.
If it complains that you've run out of free articles then just clear the site cookies and data and reload the page (click the padlock next to the url if you're using Firefox).
Thanks, it works! The site collects some kind of a fingerprint, looks like. Private mode chrome opened site asks for account, the same site in firefox, indeed, thinks I'm a new user. Smells like some dirty way of data collection.