[DownGoat]

To some degree you can trust them, as data request to Signal have been through the court systems which is public. You can actually look up and see what data they have turned over after receiving court orders to do so.

[globalise83]

Would a secret CIA subsidiary hand over data for a routine civilian court request? If anything not doing so would make their covert surveillance tool even more trustworthy and effective.

[gzer0]

The only information Signal can provide is [1]:

  * Time of account creation 
  * Date of the account’s last connection to Signal servers. 

That is all. If you want, the link below is the grand jury subpoena for Signal user data, Central District of California, in full.

[1] https://signal.org/bigbrother/cd-california-grand-jury/

[globalise83]

That's my point, if Signal were a CIA front with some kind of secret backdoor, it would probably not reveal that in response to a request from a Central District of California grand jury.