All rep is logged so if its bad we (Site Admins) can investigate it further if requested.
So ... let me check if this is right?
If you thank people they earn points.
If you give rep, the points they get are based on the points you have plus the number of posts they have made?
The rep points also increase on the 3rd friday of every month beginning with M and negative rep can be eliminated by the careful use of Vanish before washing your clothes ... erm ...
I am still not sure about it, but I will give thanks where deserved. Perhaps it is just that I am not a negative sort of person.