There are several types of "identifying" information in crypto. Knowing what is okay to share and what is not will save you from theft.
Most wallets have public addresses, these are okay to share with people as the information they provide is public.
These are frequently used by people to help troubleshoot issues. It is still a good idea to only share these with people you must transact with or who are admins in a TRUSTED group.
PRIVATE ADDRESS/KEYS and SEED PHRASES
Your private address/keys and seed phrases allow access to your wallets
They can be used to import wallets into new accounts or to recover access if a device it was saved on is lost or destroyed
NEVER SHARE THESE WITH ANYONE YOU DO NOT KNOW AND TRUST
Never send these “in the clear” either
Don’t text them or send them via regular email
Signal Messenger is one of the most secure messaging services out there. It is end-to-end, and on-device encrypted.
HOW TO KEEP KEYS/PHRASES SAFE
When you start a new wallet or account: Write these down on paper, make two copies, triple check they are accurate, and store them in separate places so that if one gets destroyed you have a copy of it somewhere.
If you ever lose these AND lose access to your wallets you will have no way of recovering the crypto assets stored there.
There are several alternatives to the tried and true, thousands of years old paper & pen
You can use one of these metal options from Trezor
LastPass has an option for storing documents and notes encrypted, if you don't have a great password for LastPass it is not as secure as storing them on physical means and storing them in a safe place.
Another option for storing these is an encrypted USB drive that uses physical buttons to enter a password. There is the possibility that if a device you plug it into is compromised, the data will be stolen. So this is only for people who are confident in their ability to secure their devices. datAshur is a good brand that doesn't cost an arm and a leg.