Even State Department-funded Human Rights Watch admits that authorities combine legal and illegal methods to obtain convictions: https://text.hrw.org/report/2018/01/09/dark-side/secret-origins-evidence-us-criminal-cases
Combining dragnet surveillance with device hacking is intended in the design of both tools. Hence, State Department-funded Signal dupes you into handing over your identity as part of the population-centric mapping. In custody, your phone will be hacked when it is taken away if it’s important.
https://xcancel.com/hannahcrileyy/status/2034273723667161480#m
The audits determined they don’t have any user information to provide. You can see this in previous government requests where the only thing provided was a timestamp of last connection to the network.