[SwordMage]

This has been changing recently and I am not sure of the current exact numbers.

You have two ratings for each faction: dynamic and full. Dynamic is the amount your have earned; full is the total faction rating including your starting rating).

So when people talk about -6000, they are refering to the full rating and that is the cutoff rating between the hate you and they hate you enough to attack.

When people refer to 350, they are referring to the amount of dynamic faction you must earn to overcome your initial rating and thus rise above the KOS boundary (if the -6000 was correct, then your initial rating would have been -6350 in order to need 350 to become non-KOS).