Signal is likely funded by the CIA and other intelligence actors:

https://yasha.substack.com/p/signal-is-a-government-op-85e

https://www.kitklarenberg.com/p/signal-facing-collapse-after...

https://www.city-journal.org/article/signals-katherine-maher...

https://drewdevault.com/2018/08/08/Signal.html

https://bigleaguepolitics.com/court-docs-show-fbi-can-interc...