A number of websites which hosted what appeared to be a next generation Xbox design documents have received takedown notices from Microsoft.
Polygon reported that a Czech site received a letter that requested the content was removed.
"Microsoft has received information that the domain listed above, which appears to be on servers under your control, is offering unlicensed copies of, or is engaged in other unauthorised activities relating to copyrighted works published by Microsoft," said the letter from Alan Radford, on behalf of Microsoft.
The letter, which has also been sent to other sites, stated at the "IEB Roadmap" was an infringement of Microsoft's copyright.
The document appeared last week and was originally hosted on Scribd. Microsoft's lawyers, Covington & Birling LLP, moved quickly to have it removed, but not before it was copied and posted on various blogs and gaming sites around the world. It featured a number of details about the "Xbox 720" due for release in 2013.
Microsoft has yet to comment on the document, but the continuing legal action seems to verify at least some of its contents.