They don't. There seems to be some confusion about how Strava works in this thread. People turn it on to track physical activity (i.e. exercise). Nobody is tracking their "military activity." They're turning Strava on when they go for a jog around the base. And then they stop it when their run is finished. If enough people on the base do this, then common routes will stand out on the aggregate map.

Nobody on a smuggling operation would have Strava turned on. That makes no sense.