Member points are given for contributing positively and taken away for being stupid. If you have -10 points, you will be banned for two days. Just as good things can come from them, bad things can too.
The most points you can get positively at one time is only one point, however, the most points you can lose at once can very from 1 to 10 depending on the crime. Ways on how to gain and how to lose member points will be added on as time goes by.