This method only works within your magazine, and will remove downvotes or upvotes on comments as well as posts.

To implement it, go to Magazine Panel -> Appearance, and enter the following in your CSS box to remove downvotes:

{span style="color:#323232;"}.vote__down { display: none !important; } {/span}

and/or for upvotes:

{span style="color:#323232;"}.vote__up { display: none !important; } {/span}

Example with downvotes removed : @13thFloor

Many thanks to @Anafroj for writing the original CSS code, and suggesting it as a way to combat trolls. Note this test shows that standard CSS works in Kbin, but you do have to replace <> with {} to get it to parse properly.

This isn't a perfect solution, but it should mitigate the amount of users that try to sink communities through downvote spam.

Thanks to @some_guy and @cre0 for posing for the picture.