"the spy service was provided with information captured from unsuspecting travellers' wireless devices by the airport's free Wi-Fi system over a two-week period."
Like what? Mac addresses? Mac address + IPs it connected to?
"The document shows the federal intelligence agency was then able to track the travellers for a week or more as they — and their wireless devices — showed up in other Wi-Fi "hot spots" in cities across Canada and even at U.S. airports."
How? Did CSEC have a deal with companies providing wifi?