Signal service doesn't store message routing meta data nor what groups you are in.
In response to a subpoena for specific user's data:
"the only information we can produce in response to a request like this is the date and time a user registered with Signal and the last date of a user's connectivity to the Signal service."
I don't know much about security so I really have no constructive criticism, obviously, one can easily make lots of investigative inferences from the information Wire collects and that is troubling enough.
If I understand correctly signal stores only metadata. My question whats the format of the metadata what kind of information does it retain. Is it anywhere close to what Wire is storing?
I would appreciate clarifications on this.