Nothing has changed as far back as I remember. I believe it goes back to sometime in the mid-1980s. The name of only the individual who is subject to the background check is provided to us, and we do our criminal record check, we do our database checks, we do checks with municipal and provincial police forces only on the individual--not on spouses, not on children, not on friends, not on neighbours.
On June 10th, 2008. See this statement in context.