Synapse: Consider hiding device names from federation
Synapse 1.34.0 brings in an option to prevent device names from being shown across federation. I think it reduces unexpected metadata leakage as device names may contain information about used OS and browser by default or in case of Element iOS full name of the device owner (this may have been fixed since then though).
# Uncomment to disable device display name lookup over federation. By default, the # Federation API allows other homeservers to obtain device display names of any user # on this homeserver. Defaults to 'true'. # #allow_device_name_lookup_over_federation: false
Now that cross signing exists there is much less of a need for other people to look at devices and verify them individually. This PR adds a config option to allow you to prevent device display names from being shared with other servers.