Unix User\nobody

I have a large amount of files that were copied directly to the Download share from my Windows 7 computer which now cannot be deleted.  I get the same message that says I need permission from Unix user Nobody. 

Why does this unix user have permissions over files I created on the share??   And how do I regain control of these files?   I can’t find a way to delete them through the WD My Book interface either…any help on this one? 

Thank you!

MrPisky