But for all its sophistication, the approach could not prevent the financial services debacle, and shareholders lost out anyway.

But that approach cannot prevent breast cancer; the best it can do is catch the disease early.

Can such an approach prevent a family tragedy and rescue an endangered business?

This approach does prevent the company from earning very high profits.

But a cooler approach might have prevented the novel being consumed by its own violent subject matter.

PaX's more general approach, on the other hand, prevents damage after the attempt begins.

But that approach could not prevent Siebel revenues from falling in each of the last four years.

This repressive approach has not prevented the use of drugs from spreading.

This approach does not prevent the banks from reflecting certain specific aspects of their trading book or a particular management model.

Could these approaches actually prevent piracy, or do you think their backers are simply mistaken?