Identity theft will be a problem no matter how identity is specified. It will be more likely to be considered unethical (and possibly actionable) if the identity being misappropriated is a real name.
I disagree with the first sentence. If I am using a pseudonym (as I am here), then it is not possible for some casual user to steal my identity in a truly “actionable” way because Jerevan Somerville is, at least on this message board, a construct. Someone might use the same name elsewhere, deliberately or otherwise, but it does not necessarily follow, nor should anyone assume, that the postings are by the same person.
In fact, the same can be said about using real names. There might another J.I. Hymas in another community. It might be you, it might not be. It would be unethical only if you could prove that someone did so, deliberately, to harm your reputation.
Not really. Or, at least, only if the purloined name is used to bring opprobrium or injury down on the actual owner.
Given the nature of discussion groups, neither is likely.
You have an interesting hypothesis in this thread, but I am afraid I find it unpersuasive.
OK. I just couldn’t think of another reason for using one’s neighbor’s name.