On Telegram this is rampant, on average probably one person per day. It shifted from e-gold scams to sex since a few months, but both are still present. People that aren't in big groups (where the spammers scrape user IDs) have zero problems, so the trick is revealing your random identifier only to those you want to contact you. Phone number identifiers are the antithesis to spam protection: we keep our ranges just full enough that we can't shorten it by a digit, but empty enough that we have small growth possibilities. You're very likely to hit a subscriber, by design, by trying random numbers.

That also sounds like a good way to limit adoption as well, at least for anyone with more the N contacts, particularly >= 2N as that means likely a minimum waiting period before you can transfer over "more" contacts since some people will never accept/reject the invite because they don't use the app much.

If it were me and I had to wait on others to accept or reject my invite before I can continue transferring contacts, I'm gonna move on.