Some of these comments remind me of when I played Freelancer and how in that game (as I'm sure many here remember) there were some systems that you just had to be really careful in because it was infested with rogue gangs of pirate thugs in powerful ships. You REALLY had to have a good reason to go there. To make things more challenging, some of those systems were inside of gaseous clouds (and sometimes with asteroids to boot) that restricted your visibility and made spotting distant targets impossible. It always made me tense up and tread carefully, and I always got the feeling that I was somewhere that I really didn't belong. It was nerve wracking, but exciting and fun at the same time. I have to admit that I've not ventured really far from the starting systems in ED, but so far, I've not encountered any particular place that made me feel like I was in danger. In other words, there's no "bad parts of town", and that seems to be what people are saying here.
That's not to say I haven't had my ass in a tight spot from time to time. On rare occasion I've dropped into a USS or got interdicted by a ship that was just pounding the crap out of my Sidewinder (yeah, I still have it) and I barely made it out with a few percentage points of hull left without even getting a single shot in. A few times, I didn't make it... "Hello? GEICO? Yeah... umm, I need to make a claim..."
I agree that ED would definitely benefit from having some star systems tagged as being particularly rough and tumble, known for being extremely hazardous to those that dare to venture into them. Of course, the rewards (high dollar missions, bounties, etc.) should also be available to give you incentive to take the risk.