"White hat cracking" involves security testing by arrangement. "Grey hat cracking" seeks to identify insecure systems and inform administrators/users of vulnerabilities. "Black hat cracking" involves accessing systems. Counterattacks on phishing servers, spam sources, and malware distributors are held up as "ethical cracking". And "hacktivism" involves cracking for a "higher purpose".
Is it possible to crack systems and still be ethical? Support your position.