Grid attacks. How to minimize their impact ... ?

Ah, ok. I seem to recall that. Wasn't there another, with floating ghosts or something?

You know, if they'd ever give a client-side API, so we could script sex-doll NPC's, that would go a long way to solving this problem. See, my Batgirl love-doll fetish wasn't just to fulfill my fantasies, it was a security feature! Yeah...

Wild Slime Follow Drone?

There was Lordfly's zombie invasion of halloween '04. That wasn't really an attack, just people didn't have much of a sense of humor about the whole thing.

In the real world, you do not have a god given right to enter, stay on, or litter other people's property without permission. If you do so, and are caught, you are likely to be prosecuted. In some places, you can even be legitimately fired upon and killed by the owner.

In SL, these rights are granted to you by default, and there are no penalties for infringement. This is wrong, unheard of, and outrageous if applied to anything else.
So yes, you should definitely not expect to be able to wander around the world rezzing starax's stuff. Normal people don't expect to throw parties in strangers' properties, they go to parties at friends' places or public places, where they are explicitly allowed, when explicitly invited. You do not enter a person's home without ringing a doorbell and asking to be let in.
Base it off the friends list for all I care, just don't leave the whole stupid grid open to everyone like that. It's silly and unnecessary. Most places are empty anyway, people congregate in clubs, malls, and each other's homes.
If you had bothered to read what I wrote, you would see that I proposed a way by which you could have a public place - join the land's group.

In the real world, you have the ability to use, abuse, or damage other people's property by entering their property without their permission. In SL you don't. In the real world you have the ability, when you're on someone's property with their permission, to pull a paperback out of your pocket, read it, and set it down on a table for a moment while you're talking to them. In SL the only way to emulate this ordinary, everyday, non-invasive, non-intrusive thing is to rez it.

I'm not talking about abusive behaviour here. I'm not talking about something that you'd haul in access controls over.

We're talking about being able to perform the equivalent of simple, everyday, non-abusive, non-intrusive action of pulling somethng out of your pocket and putting it on a table, in a place where that's normal and expected, without going to the landowner (who may not even be online, if you're visiting with a friend who's renting or sharing) to add your name to a limited access list.
You're liable to be prosecuted for setting a book down on a coffee table?
Ah, SL is definitely ahead of the real world there. You can be fired upon, killed, or hurled bodily off his property by the owner. And you don't even have to do anything to them!
In SL you're not granted even the ability to violate the equivalents of the property rights you're talking about without a heroic effort and usually collaboration by the landowner. You can't harm so much as the hair on another person's head without their permission. The idea that it's outrageous that there's no restrictions on your rights to do something that you're unable to do in the first place is, well, outrageous.
Why not? It's the SL equivalent of carrying cool shit in your pockets to show people.
Normal people don't expect to find themselves crippled when they tag along with a friend.
It doesn't MATTER what you base it on, you're just adding an annoying extra step to the most harmless of actions without providing even the slightest protection against grid attacks.
In other words, they congregate in places that exist on every sim and which could be trivially used as the seed locations of grid attacks.
15 group limit, horrible group control tools, and by joining the land's group you'd suddenly find yourself with the ability to do all the stuff that you normally can't do to other people's things. I don't let just anyone into my land groups... that's crazy.