To clarify my earlier post. If someone adds one of my photos as a favorite, or starts following me, I'll check out their photos.
If they have nice photos that I'd be interested seeing regularly, I'll follow them.
If they have photos, but their not really my bag, I just move on with my day.
If they have nothing to share, but are brand new, I give them the benefit of the doubt and move on.
If they seem weird, or seem like their building a collection of other peoples photos for some reason, without sharing anything, I block them...with the knowledge that they can still see my photos, but can no longer put them in their collections. (i.e. I have a couple "body paint" photos that aren't really all that special, that I took for a friend that was studying SFX makeup. Those tend to get "Faved" by people that seem to not own a camera.)
Honestly, I get so few Favorites or Followers as to not really matter most of the time anyway.