Don't you have to keep paying for the sim, otherwise someone else might "steal" your account once your phone number gets reused?
Stop asking for phone numbers!
My mother has my phone number. A few of my closest friends and family have it. That's it. I have like 10 actual people on my phonebook. My phone provides immediate 24/7 access to me, and there are very few people who are close enough to me that I want to be able to reach me at any time.
Some Silicon Valley company with an inflated sense of importance is never on that list...
Moxie should know better, but this blog post repeatedly boasts about privacy while not addressing this at all. Getting basic encryption into the hands of the masses is a laudable goal. But when the popular threat model changes (eg pocket computer compromise incident to arrest at a protest - an "evil raid" attack), you either need to adapt or you've become an attractive nuisance.
Specifically I'm envisioning an attack where say ten protestors are arrested and found to have a shared contact, and then the police turn that phone number into a real world identity and go after that person for organizing.
Also the people doing shady things are generally hopping accounts regularly anyway.
Also, anyone who had communicated with you before the switch would see a “safety number changed” notification if the number became affiliated with a new device.
EDIT: Found the related docs, appears they had been edited since I lasted looked at them; for example, you can now disable PIN reminders:
https://support.signal.org/hc/en-us/articles/360007059792-Si...
And yes, “anyone who had communicated with you before the switch would see a ‘safety number changed’ notification if the number became affiliated with a new device” is correct, though so is my statement about new numbers adding the number. To be honest, I have caused the alerts to happen before, the other user had no idea what they meant, didn’t say anything, just clicked okay.