In every system which rewards points and badges people are bound to game it from time to time.
I see it like this:
There are games which have little to no negative effect (e.g. voting a lot of questions and answers; flagging posts; reviewing posts; editing a tag wiki);
There are games which can have some negative effect, but still have a positive side (e.g. editing a lot of recent posts - especially in a spree of five-six edits at once);
And there are games which have little to no positive effect (e.g. editing year old posts for minimal changes in order to get an Archaeologist badge).
Lately I've noticed many old posts that were bumped with very minor changes. I rejected a few edits before when the post was too old and the edit was not substantial.
I wanted to bring this to the attention of those who read this meta:
If the edit is minor please approve it only if the post is not very old. Changing a book's name from normal letters to italics on a post from 2010 is hardly something worth approving.