The person has to identify themselves to the extent that they qualify as a requester under the legislation. So they need to establish that they are actually a resident of Canada. Aside from that, they need to have somewhere where the information can be sent to them. Some requesters, as I said before, deliberately do not identify themselves, or use a proxy or somebody else to make a request on their behalf. That's quite normal.
On October 25th, 2011. See this statement in context.