Apparently, there are some editors of academic journals who will readily send manuscripts out to “non-preferred reviewers” – the specific people that authors specify who they don’t want to receive the paper for review.
I think this is all kinds of messed up.
Is this a simple, clear-cut issue? Well, no. There are a lot of factors at work on the surface, and a lot going on under the surface that the involved parties might not be aware of. However, notwithstanding the complexity of the issues at hand, it’s hard for me to imagine a circumstance where this kind of action would be advisable (and I’d like to be clear that this is a practice that I do not engage in).