On Friday 9th of June Microsoft announced that it would be retiring the Docs.com platform, effective as of Dec 15th 2017, at which point all content would be deleted:

The homepage of Docs.com with the banner advising it will soon be retired in mid December 2017
An in-depth help article is available to assist you with managing the impact of this announcement, including advice for how to migrate your content to other platforms such as OneDrive For Business. Given many school users already have Office365 accounts the following advice is helpful:
For Office 365 Users with OneDrive for Business
We can automatically back up all compatible content to your OneDrive for Business account if your Administrator enables the auto-migration service for your organization (this option is available as of June 19, 2017). If you would like your school’s or company’s Administrator to initiate this process for you, please contact them and include a link to this article.
You can also choose to log in to Docs.com and follow the auto-migration prompts yourself. When the process is complete, you will find all compatible content you had previously published to Docs.com backed up to your OneDrive for Business folders. The original content on Docs.com will thereafter only be available to view, download, and delete.
The help article will be updated after June 19th 2017 with further information specifically for O365 Administrators so they can support their users.
Microsoft is encouraging regular users of Docs.com to explore SlideShare.net as the recommended replacement platform for sharing content publicly.
SlideShare was acquired by Microsoft as part of LinkedIn.com and allows users to sign in with either their LinkedIn or FaceBook profiles to start sharing and commenting on the platform. From the announcement article:
Following Microsoft’s acquisition of LinkedIn, SlideShare has joined the Microsoft family, and represents the ideal platform for publishing your Word, PowerPoint, and PDF content with its audience of 70 million professionals, and vast content library
There is six months remaining before the retirement of Docs.com and the subsequent deletion of all content on it. If you’re a regular user of the service it is time to get thinking about backing up your content to OneDrive for Business and migrating your public content to SlideShare.