Twitter:

We observed a particularly high volume of requests coming from individual IP addresses located within Iran, Israel, and Malaysia. It is possible that some of these IP addresses may have ties to state-sponsored actors.

And:

When used as intended, this endpoint makes it easier for new account holders to find people they may already know on Twitter. The endpoint matches phone numbers to Twitter accounts for those people who have enabled the “Let people who have your phone number find you on Twitter” option and who have a phone number associated with their Twitter account.

In the Twitter app, do this:

• Tap your Twitter avatar.
• Tap Settings and privacy
• Tap Privacy and safety
• Tap Discoverability and contacts

Turn stuff off.