Is it illegal to give out someone's phone number, email address, etc. w/o their knowledge or consent?

My wife’s friend is seperated from her husband and staying with us. He is sending her multiple emails, texts and phone calls to her each day, now he is coping what looks like everyone in his address book and including our home address and phone numbers to all of these people.

Incoming search terms:

• illegal to give out email
• is it illegal to give out someones phone number
• is it illegal to give out someones phone number online