Ethics are either black or white - there are no shades of grey in my view, as I posted before.
But there are some situations in business life where ethically it seems OK, but morally its not so clear. In such a situation, an individual's value systems determine what's right or wrong and there is no one right way.
Does it matter what business the company you work for, is in ? If your company is an IT company or a soap company or a telecom company or a steel company, there is no issue.
But would you work for a cigarette company ? Would you work for a company that makes land mines ? Would you work for a company that buys "blood diamonds" from Africa ? Would you work for a logging company in the Amazon?
Or, does it not matter what business your company is in, as long as what it does is legal and you do your job professionally ?