https://www.engadget.com/2018/04/26/microsoft-shut-down-halo-online-eldewrito/
"While we are humbled and inspired to see the amount of passion poured into this project, the fact remains that it's built upon Microsoft-owned assets that were never lawfully released or authorized for this purpose. As this project reverberated across the community, our team took a step back to assess the materials and explore possible avenues, while Microsoft, like any company, has a responsibility to protect its IP, code and trademarks. It's not optional in other words.
BTW, we're not 'shutting down the mod' or going after the Eldewrito crew - we're enacting action to remove the Halo Online code and packages from places it's being hosted."