Fundamentally, the reason I think that homework assignments (beyond show me fizz buzz in your favorite language) are ethically wrong, is that the cost of hiring someone is the company's not the employee's.<p>Employee's are asked to give up a lot when the work for a company, yes they're paid for their time but it goes beyond that. Many companies require that all inventions and patents belong to them during your tenure there. Many also have no moonlighting policies - meaning you're productive work life is essentially theirs.<p>An prospective employee is also often taking a risk that could sink them financially. The reverse is rare for large companies, especially since employee pay is a tax write off.