Reports the current number of users classified as transparent pass-through — allowed to send traffic without having been individually authorized. This population exists because cssgCfgTransPassThroughEnabled is on, so this gauge is effectively the live headcount of traffic allowed through before or without full authorization, a number an operator watching for abuse would want to keep bounded rather than growing indefinitely. If cssgTalPassthroughUsers unexpectedly climbs into the thousands on a network that expects nearly everyone to be quickly identified, that suggests TAL identification is failing and traffic is defaulting to pass-through far more than intended.