1) Only the U.S. even has a copyright office that requires registration. The reason that most of these companies are international is because they are addressing problems that are more local. In those countries, there is no verification of who created a work and at least these services can bear as some witness.

2) Also, even in the U.S., the court of law is not the only court to worry about. Most cases never reach a point where the law itself comes into play. The court of public opinion is also worth concern, especially for artists trying to build a career and these services can assist at least some with that.

3) The licensing issue is universal, not just to these services. Any time you submit a work to anything you should read the terms carefully and weigh what your future plans are for the work. Make sure that the licenses are compatible. That's just good practice.

4) C-registry.us does provide visual search and others are working on it, including Myows.

5) The orphan works problem originates with older works (though the eCO really doesn't introduce anything to fix it) but the solution may impact newer works as well as older ones. As such, artists need to be prepared to make sure their works can easily be identified as their, just in case.

Hope this helps!

I also disagree that these sites help to solve the orphan works problem. They don't seem to do a better job of tagging the works, none offer visual search, and none of them contain the pre-eCO copyright database, which is the real origin of the orphan works problem.