Funny how I had 21 karma points before I posted that comment, which got 4 down votes and another comment got 3 upvotes, but now I have 15 karma points.
How does 21 - 4 + 3 = 15?
2) I very often open many links without thinking about which domain it's on.
3) A post's karma will never show below -4, even though the real karma could be way lower.
Here's a tip though - you can't cash it in for prizes, don't worry about it.
For the record, I don't care about karma points, I care about whether or not the system works correctly.