Whose Fault is a Supplier's Lack of Ethics?

An interesting article appears in today's NY Times by Steven Greenhouse with the headline "Suit Says Wal-Mart is Lax On Labor Abuses Overseas." To summarize, a labor group filed a class action lawsuit aganist the retailer for not enforcing its code of conduct for overseas suppliers. Several codes were broken such as, payroll violations, physical abuse and long hours. Some of the accounts are abhorring, including one worker that was slapped so hard her nose bled and another employee was locked inside the building overnight. But is this Wal-Mart's fault?

Wal-Mart contends that they have 200 inspectors that search 30 factories a day. With 5,000 factories it will take them approximetly 167 days to inspect them all, which shows a real commitment to addressing the problem.

The article continues to explain that if the workers file in their home countries they face arrests and physical attacks. This is not unlike the United States from the 1800s to the 1940s. Paid by the piece, seamstresses often worked 16 hours a day and their income rarely exceeded bare subsistence. This resulted in the forming of unions, which virtually whipped out unions in the US by 1938.

I'm no international labor expert, but why isn't this an option instead of the fruitless lawsuits?