Judging by how fast my comment above got deleted, it's definitely a mod or a group of mods.Do you mean an organized group of users who are downvoting? If so, I haven't seen evidence of such a group on HN. There is a strong reaction by many community members to what's perceived as uncivil behavior, as the HN community as a whole values the quality of the forum.
By "mod", I mean any privileged user.
The HN mods are dang and sctb. They are indeed privileged users, as they have the ability, among other things, to ban users. They've also got a lot of responsibility, which they take very seriously and with — from my perspective — great care.
You're admittedly new to participating on HN (or at least this is a new account). Please take some time to reflect on the community reactions to your comments, and how your personal views of civility and substantiveness may differ from those of the community as a whole. This goes as well for assumptions of how the community works and behaves. This isn't meant as a value judgement of your views, just that they appear to differ, if at least a little. After all, this is the community you'd like to participate in. You can also observe how others behave on the site to better understand community standards.
Please take this in the spirit it's intended. As one HN user to another, I'd like for you to have a positive experience as well as contribute constructively to HN.
If you have questions that aren't answered by the guidelines and FAQ, you can contact the mods by email (see the contact link in the footer). I've also found general search engines (e.g., DuckDuckGo, Google) and the HN search tool (in the footer) very useful to find answers to many questions I've had about the HN community.