Testing Race Conditions in Java

Can you spot the bug in the following piece of Java code?

/** Maintains a list of names. */
public class NameManager {
  private List names = new ArrayList();
  /** Stores a new list of names. This method is threadsafe. */
  public void setNames(List newNames) {
    synchronized (names) {
      names = new ArrayList();
      for (String name : newNames) {
        names.add(name);
      }
    }
  }

Продолжение:
http://google-opensource.blogspot.com/2009/10/testing-race-conditions-in-java.html