But that’d already entail control over the whole Signal AWS in- and egress as well as any VPN you may be using and/or your local ISP. And then you still have to prove the actual link to the natural person. At that point we’re speaking of a threat level assuming the US DoD as adversary. While not impossible, I think if you’re willing to pick that kind of fight, you’re clever enough not to rely on Signal (or most digital communication).
Signal is not WhatsApp, there aren’t a lot of data points linking your communications to end points in the same way Meta does link them.
Krill, a Rust RPKI tool 🦐