Why not simply make downzappers accountable for their actions?

If someone posts something and boosts it they are being open about and accountable for their actions.

In such a case stackers should be free to downzap content that is crowding the front page but downzappers currently seeking to covertly silence particular viewpoints would also now be accountable.

It is the covert nature of the downzapping that is encouraging it to be used to censor content.
If the censor/s are identified then they are then also accountable.