And if you shoot people in high-sec or low-sec, you take a hit to Security Status, and if it gets too low, you'll get nuked just for jumping into a high-sec system, and the only way to raise it is to grind pirates for hours. And if you shoot someone in low-sec and jump to high-sec within 15 minutes, you get CONCORDed anyhow. And gates and stations won't allow you access for 30 seconds after shooting someone. And, of course, 0.0 is divided into NPC sovereignty and Player sovereignty which affects whether or not you can dock in their stations in the first place (but you have an aggression timer of 30 seconds even for stations you own), and in addition to the police (CONCORD), if you have a low enough standing with one of the Empires, their Navy will attack you in their space. And different rules apply in Faction Warfare low-sec, where some factions can shoot at declared players of the other faction. Oh, and because of rounding, there are a handful of 0.0 systems that actually hit you with security status penalties if you shoot people in them.
Yeah, EVE is complicated.