> then blocking the number & reporting spam
I think it's also helpful to be prompt if you'd like to help others; A campaign will use e.g. twilio numbers leased for a matter of hour, then release it. If you wait too long to report spam, you damage the number's reputation without actually punishing the hyperactive spammer.
Isn't Twilio complicit? and isn't it deserved that random Twilio customers, who are funding an illegal organization, get banned? If there is no consequence, Twilio will continue. I'd happily fund a campaign to drive Twilio to bankruptcy.
If twilio does not want its numbers to be marked as spam then it needs to do a better job of not being used to send spam.