Foreign Invasion

Recently Justice Ginsberg on the U.S. Supreme court has spoken a great deal about using citing foreign law in U.S. Courts. This has upset many people, and rightly so. There are two major problems with using foreign laws to strike down U.S. Laws. The first is the fact that foreign law is incredibly diverse; who decides what foreign laws we are going to use? The second is that given the diversity of foreign law, almost any american law can be view as 'out of step with the rest of the world'.
When Justice Ginsberg expresses her belief that we should look abroad and 'listen' more to what other courts have to say, does she mean to concider all courts equaly? Is she as open to the various branches of Muslim law which strip women of many rights Ginsber herself worked hard to promote as she is to the more liberal European laws? I certainly hope not, and I seriously doubt that she does. But if she does not, then how does she or anyone else determine which foreign laws should be used as precident and which ones should not?
The answer, sadly, is that judges like Justice Ginsberg pick and choose what laws they like and which ones they do not like. But why? If judges are there to uphold the constitution and to serve as a brake on progress as the Founders clearly intended, why do judges on many of the nation's courts feel the need to reference foreign law? It may be because Justice Ginsberg and other judges like her (such as former Supreme Court Justice Sandra Day O'Connor) want to refasion the American legal structure in a manner more pleasing to themselves, and they are too impatient to wait for the political process to grant them the results they desire.
If foreign law becomes a dominant source for precedent in the U.S. Judges who wish to legislate from the bench will have almost unlimited power; for any decision they wish to hand down they can find some foreign law that will lend some shadow of credence to what they want.