Honestly I think the only significant difference is in branding: Flock isn't consumer-facing and is explicitly marketed for tracking people's movements. The major tech companies that make your phone, browser, maybe a few smart home devices with always-on microphones or cameras, all have more data about you and your habits than Flock could ever obtain, and with us paying for the privilege no less. I get that the average person doesn't care when the product works as advertised, but I don't think that's healthy. People should care as much about privacy when it's Google or Meta as when it's Flock.