The rules being that I wouldn't dump on any lowbies. I would invade, scope them out, maybe take a swipe, size up their gear and black crystal out if things didn't add up. If I did stay to give them a fight, it would be with early game gear not upgraded past +3 and I would drop them a useful but not gamebreaking weapon for their troubles (ie, Magic Longsword +2 or Divine Mace +3). Here are the findings of my griefing experiment.
1) The BB Glitch is rampant. I would continually run into guys in end game gear who would get two shotted by a spell or combustion. Thinking I was fighting a guy of superior level and game completion, I would later find their vitality equal to my own lvl 20 toon.
I would also run into something like a thief in starter gear who had killed everything in the burg and encouraged me to fight. Thinking I was fighting a legit lowbie, I would downgrade and get chain BS'd by a lightning dagger.
We all knew it was going on, I was just surprised to see the extent.
2) Dark Souls is getting new players everyday. I would check trophies to confirm lowbie status and a good portion had only the first three in their collection.
The population isn't dwindling off.
3) Lowbies/newbies can get emotional. They freak out when they get invaded. They run all over trying to summon phantoms or try to ambush you from around corners. This is expected. But then they send 'thank you' messages after you drop them a weapon and give them a fair fight (win or lose).
4) Lots of people are down for fist fights. The best place is on the wooden bridge so the thing doesn't go on forever.
5) NPC cosplay invasions are my new favorite past time. Invading Lowbies as Dusk puts you on near equal footing . . . . all you can do is hide your weapon or turn into a barrel.
Which brings me to a question I have been considering.
Why don't we have an NPC War?
Try beating anybody who possess some amount of reasonable skill as Ingward - it's a blast. All you can do is poke at them with your catalyst because they can dodge your spells and even if you parry with the ghost knife, the catalyst can't follow up.
Solaire and Kirk are easy to fight as, but make an attempt at dressing up as Vamos and coming out victorious.