LastPass, a password manager, revealed Monday that it had been the target of a hack that compromised account email addresses and several security elements used to encrypt user data. "We are confident that our encryption measures are sufficient to protect the vast majority of users," the company said in a statement. "Nonetheless, we are taking additional measures to ensure that your data remains secure." LastPass stores multiple passwords for users' various online logins and uses one master password to access them. Users most in danger of being personally hacked as a result of the breach, first detected Friday, are those...