The agency is responsible for foreign signals intelligence and for protecting the Canadian government's electronic information and communication networks.
Since the events of 9/11 and Canada's subsequent 2001 Anti-Terrorism Act, the CSE's capacities have expanded significantly, in terms of legal mandate, available technology, and financial resources.
[5] Per CSE's own description,[6] all of the agency's activities must be necessary to fulfill their relevant mandate; proportionate to the risk being mitigated or the foreign intelligence of interest; effective at protecting the privacy of Canadians; and as minimally intrusive as possible.
Even though metadata does not include the content of the communication itself, it yields a substantial amount of information about its source devices, users and transmissions.
A national security measure to track patterns of suspicious activity, the Canadian metadata surveillance program was first implemented in 2005 by secret decree.
To reduce this allegedly inevitable incursion of privacy, the agency takes measures such as limiting the length of time that metadata can be stored, restricting access to metadata to authorized CSE personnel, redacting any identifying information about Canadians when sharing intelligence with allies, and cooperating with the CSE commissioner's review of activities.