There is also the issue of legal personality, which applies to corporations and not to governments or religions.

The corporation actually seems to me a great example of a non-biological, non-software optimization process, and I'm surprised at Eliezer's implicit assertion that there is no significant difference between corporations, governments, and religions with respect to their ability to be unfriendly optimization processes, other than that some people of a certain political bent have a bias to think about corporations differently than other institutions like governments and religions.