It does in fact ask the user to login before giving them a download link. The files themselves don't appear to behind a login-wall since people are posting them far and wide. But the website very much implies that you need to register.
This is a link specifically from the Docker store. Download pages are also linked from multiple places in the documentation, binaries are installable via Docker's package repositories, and generally available far and wide. This is a misleading, sensationalist headline, i.e. clickbait.
