Shortly after criticizing an answer for lacking sources or any detail, I noticed that three of my old posts were downvoted within the span of a few minutes. I suspect retaliatory downvoting considering that all of them occurred within a few minutes of each other and these posts had been sitting dormant for weeks.
I reported the incident and waited 24 hours for the Stack Exchange serial downvoting script to reverse it, but nothing happened. I was under the impression that SE took this seriously, so my question is, what does it take for such obviously retaliatory action to be considered "serial downvoting"? 4 downvotes, 5...?