In ST, we've run into users signing up in more than one organization. The ST
admin can find this by opening the user page and doing "find" in the web page,
but ordinary TC users can't find people in other orgs, I think. It would be nice
to have a general "search" capability to search for strings within the email
addresses and user names of the ST, so people can see if users are signed up
under different orgs.