The Net Negative Producing Programer

It has been well known for a long time that there is at least an order of magnitude difference between the most productive developers and the least productive. But if you've been in the software industry for any period of time, you've probably met this person: the net negative producing programmer (NNPP). This is the person that is so bad, that they actually have a negative effect on team productivity: you would be better off not having this person on your team.