You are subject to attack by faction navy police (not CONCORD, except in systems where CONCORD holds sovereignty) if your security status is:
<= -2.0 in 1.0
<= -2.5 in 0.9
<= -3.0 in 0.8
<= -3.5 in 0.7
<= -4.0 in 0.6
<= -4.5 in 0.5
If your sec. status is <= -5.0, you are a kill-on-sight target to other players as well (including podding), in all levels of space.
If your faction standing is <= -5.0, that faction's navy police can attack you anywhere in that faction's space.