I'm quoting the government, not "a reliable source" or all the genie bloggers that jumped on this story.
The 1921 Census of Canada
"Census returns after 1916 are in the custody of Statistics Canada, not Library and Archives Canada. The records are closed under the Statistics Act and the Act to Amend the Statistics Act [www.parl.gc.ca/common/Bills_ls.asp?lang=E&Parl=38&Se...
]. Under the legislation, when 92 calendar years have elapsed since the taking of a census, those records will be opened for public use and transferred to Library and Archives Canada.
The 1921 Census was taken on June 1st, which means that it will be in the
** custody of Library and Archives Canada on June 1, 2013.<<--------------------------------
Our intention is to make it available to researchers online, in the same format as previous censuses, as soon as possible after that date."
"Closed for 92 years under the Statistics Act to protect individuals’ private information,
** the census data is being INDEXED so it can be mined for historical and genealogical research as soon as possible.** " http://www.bac-lac.gc.ca/eng/news/Pages/2013/1921-census.asp...