“ethical hacker”

Is the expression “ethical hacker” an oxymoron? (a) Do you agree that some individuals should be allowed to be “certified” as hackers to work on behalf of industry or for the interest of other organizations? (b) Do the kinds of activities permitted by certified hackers in the CEH program raise any moral issues? Explain. Please elaborate (beyond a yes or no answer) and provide your “theoretical” rationale in support of your responses.