I'm European using signal, I frequent in two countries very often (not neighbouring countries) and for the past two years I've noticed more and more people using signal.
Ditched whatsapp half a year ago and haven't had problems. Some friends use both signal and whatsapp.
Not saying many in whole Europe use signal but it certainly is not only popular in US.
Edit: but not saying using signal will change anything if this bill passes. No matter what popular app we use we are going to have no privacy at all if this thing passes...
In case anyone is still bumping into this thread, I'll post the community here that was created after this amazing thread: !sillydrawingrequests@sopuli.xyz.
The instance I recreated this community on (sopuli.xyz) has been up for a long time and I believe it will stay since the admin is open, active and has been running the instance for years.
Definitely Old Man's War if you like Scalzi's humor!
The book series was great and really funny while exploring interesting, deep and sometimes dark topics.