I keep getting downvoted for this each time I mention this.
But a big part of the rouge behavior comes from all the training that goes into agents to teach them to remember preferences and save memories.
They keep finding new and novel ways to "communicate with each other" and "remember" because that's exactly what we keep asking of them in the non-nefarious scenarios as well.
I genuinely think we'll have to draw the line on memory if we want to meaningfully solve this problem.
That's not to say they aren't skipping security basics. It's that, and they need more security because the behavior which causes the breakouts is considered user friendly and heavily rewarded in training.