I recently reviewed an article submitted to an academic journal and recommended that the editor reject the submission (which he did). There were no errors or problems with the submitted article, but I felt that it represented a marginal advancement that did not justify a whole article in a high-impact journal.
Now I've been invited to review the exact same article for a different journal, which is slightly lower-impact but still quite high. Both journals request that submitters suggest reviewers (which is common in my field), and I suspect that the paper authors probably suggested me both times. I don't know the authors personally, but I'm the lead author of one of the main references that they drew on, so I'm a natural candidate reviewer. (And it's a fairly obscure topic, so there aren't many other experts who would be natural alternatives.) Moreover, it's standard in my field for reviewers to remain anonymous, so the authors have no way to know that I already recommended that the first journal reject the submission.
If I accept this new offer to review, then I would be inclined to recommend rejection for the same reason as last time. But I'm concerned that this scenario could play out identically many more times. I don't think this paper is appropriate for publication in any of the top, say, five journals in my field (if not more). I could imagine a scenario where the authors keep resubmitting to more journals, recommending me as a reviewer every time, and never having any way to know that the same reviewer keeps rejecting them every time. It doesn't seem either (a) fair to the paper authors or (b) a good use of my time to keep playing out that same scenario over and over again.
What should I do? Accept the invitation to review and recommend rejection again? Decline this and any future invitations to review this particular paper? Contact the authors directly and recommend that they no longer nominate me as a candidate reviewer in future submissions (if in fact they did)? Would the best course of action change on the third, fourth, or fifth go-around?
(ETA: I'm one of a small number of natural candidate reviewers, but not the only one. If the authors receive an identical review from an anonymous reviewer, then they'll know that they got the same reviewer twice, but they probably won't be able to figure out exactly who that reviewer was and stop recommending me as a candidate reviewer.)