Remote attestation is another technology that is not inherently restrictive of software freedom. But here are some examples of technologies that have already restricted freedom due to oligopoly combined with network effects:
* smartphone device integrity checks (SafetyNet / Play Integrity / Apple DeviceCheck)
* smartphone device integrity checks (SafetyNet / Play Integrity / Apple DeviceCheck)
* HDMI/HDCP
* streaming DRM (Widevine / FairPlay)
* Secure Boot (vendor-keyed deployments)
* printers w/ signed/chipped cartridges (consumables auth)
* proprietary file formats + network effects (office docs, messaging)