Their quality control must be slipping.  The unwound stings (e, b, g) each have 3 or 4 tiny black deposits that feel like raised, scratchy bumps or grains of sand on the strings.  They do not scrape off easily, either.  I have never seen this on guitar strings before.  If you are sliding your fingers up or down the strings, you definitely feel them.  They are an unnecessary distraction from the playing experience as well as uncomfortable.