What code did they steal, exactly? They re-implemented all of the functionality, and I'm not sure they took take the JS either. So at this point, it leaves CSS

What code did they steal, exactly? They re-implemented all of the functionality, and I'm not sure they took take the JS either. So at this point, it leaves CSS + Look&Feel, and I think they took some icons, though that seems like more of an oversight as it's still a young project from the looks of it. I don't see this as any different to such works as OpenTTD (Transport Tycoon Deluxe) and CorsixTH (Theme Hospital). Both open-source remakes of the popular closed-source games. Obviously they don't bundle the media (graphics, etc), and just ask end-installers to point to the installation files of the originals. You could argue that hot-linking css is quite similar to that, though not exactly. The real problem is them putting this not-yet-sanitized-of-all-copyright-infringment onto a public-facing site with a domain and everything. If it was still on Github, then that's fine. But they jumped the bandwagon a little too soon, and people are escalating it incredibly quickly.