Freek Lijten, a developer at Schiphol, makes the case for just setting a sane default value instead of throwing an exception when invalid input entered the application.

I didn't think much of this, but I've seen a major drawback lately while working on a site that is a bit bigger than I was used to. With over half a million visitors a week and lots of scrapers, bots and other stuff visiting, these exceptions and fatal errors clog up logging quite a bit. Not to the point that we can't handle the volume, but it generates false positives in monitoring channels and it is something we do not want to act upon anyway.