When I was reading The Seven Biggest Dick Moves in the History of Gaming, I was struck by the number of people who are strongly motivated to cause misery to others [1], apparently for its own sake. I think the default assumption here is that the primary risk to ems is from errors in programming an AI, but cruelty from other ems, from silicon minds closely based on humans but not ems (is there a convenient term for this?) and from just plain organic humans strikes me as extremely likely.
We're talking about a species where a significant number of people feel better when they torture Sims. I don't think torturing Sims is of any moral importance, but it serves as an indicator about what people like to do. I also wonder how good a simulation has to be before torturing it does matter.
I find it hard to imagine a system where it's easy to upload people which has security so good that torturing copies wouldn't be feasible, but maybe I'm missing something.
[1] The article was also very funny. I point this out only because I feel a possibly excessive need to reassure readers that I have normal reactions.
I suppose I will go with statements, rather than a question: I suspect the returns to caring about ems are low, I suspect that defining, let alone preventing, torture of ems will be practically difficult or impossible; I suspect that value systems that simply seek to minimize pain are poor value systems.
Fair enough, as long as you're not presupposing that our value systems -- which are probably better than "minimize pain" -- are unlikely to have strong anti-torture preferences.
As for the other two points: you might have already argued for them somewhere else, but if not, feel free to say more here. It's at least obvious that anti-em-torture is harder to enforce, but are you thinking it's also probably too hard to even know whether a computation creates a person being tortured? Or that our notion of torture is probably confused with respect to ems (and possibly with respect to us animals too)?