A federal website that informs the public about data collection has gone down, causing concern among advocates. The site went offline last weekend and was only partially restored this week. Data was missing after Aug. 1, according to dataindex.us, a group monitoring federal data changes. As of Thursday, the website's landing page stated it was “undergoing revisions.” Emailed inquiries to the Office of Management and Budget and General Services Administration weren't returned. Former Census Bureau official Chris Dick said no one outside the federal government knows what is happening with the site, whether it is technical difficulties or something more serious.