@andrew_bidlaw You can simply see this data on any Friendica instance if you have an account. Just hover your mouse over the like/dislike numbers, and you can see who upvoted/downvoted shit. You can even receive notifications about this on your own posts, just as on Facebook.
To me, it was funny back in the day to see all tankies brigading to downvote me on any single post or comment I made, the moment I started showing my political stances 😆 (yes, even stuff posted before that had no political stuff in them, lol). But yea. To some people, this might be a drawback.
The good thing, however, is that neither Kbin nor Friendica show you a centralized place in your profile to see what did you downvote. You just have to search every post you can find to see this info.