I like the idea of the nets very much, but I am confused by the harpoon approach.

I understand how the harpoon allows to snag a satellite, and than pull it out of orbit, but I can hardly believe that the harpoon impact in itself does not create additional debris. And given that even the slightest speck of dust at orbital speeds is amazingly destructive in a collision, 1 intact satellite might be less dangerous than 5 small parts of metal produced by an attempt to remove the intact satelite