Actually Mozilla analyzes and stores the user's surfing data to allow it's customers to direct ads to the user's preferences. I actually don't understand why so few seem to bother. I think it's a quite big deal. Same with these telefonica chat thing.
Regular telemetry data. Not surfing data. And certainly not sold.
Hello doesn't collect data passively either; using the video chat can of course lead to data collection though I doubt it does (but you would have to assume that can happen for any non peer-to-peer service of this kind since there will always be a server side component which you can't verify)
