unless you've contacted moderators personally first and found them unresponsive

I admit that this pretty much happened, only instead of "unresponsive" it was "responded, but then did nothing". :(

See also this.

Alright, but

1) Overly risky for whom? I personally don't feel I have exposed myself to any risk other than vindictive downvoting, and if that happens (it hasn't yet) I trust that the resulting karma issues won't affect my participation much.

2) As far as I know LW doesn't have a well set-up report & moderation system. I even searched for the official rules of conduct and only found a page on what people should not talk about (not on how they should behave generally, or the policy for bans and banned members). I don't remember seeing a list of all the mods on LW or which of them is currently online. Even Viliam Bur said here that it might take even mods a long time to get to the bottom of such an issue.

3) Some people who have an interest in knowing this (e.g. people who have been the targets of mass downvoting) might have been duped otherwise, and I view this as an intrinsically bad thing.