The Art of Invisibility: The World's Most Famous Hacker Teaches You How to Be Safe in the Age of Big Brother and Big Data

by Kevin D. Mitnick

You can always check the site www.haveibeenpwned.com to see if your account has been compromised in the past.

First, strong passphrases, not passwords, should be long—at least twenty to twenty-five characters. Random characters—ek5iogh#skf&skd—work best. Unfortunately the human mind has trouble remembering random sequences. So use a password manager. Using a password manager is far better than choosing your own.

prefer open-source password managers like Password Safe and KeePass that only store data locally on your computer.