[vbit]

> SMSs written to appear they are from someone that knows the recipient

I don't think this means they are sent from numbers known to the recipient. Only that the content is written such that it appears to be from someone who knows the recipient.

I don't know if actual spoofing is possible.

[schwarrrtz]

Yeah, if you look at the codebase it just selects a random string from an array of prewritten messages and sends that.