https://github.com/steemit/irredeemables/blob/master/full.txt
Upvotes from the accounts on this list are 'mystery' votes, as these accounts are completely censored presently and upvotes from them are not named. All of their posts and comments are never shown on front ends today.
There are means of revealing them, but those means are almost mythical, they are so unavailable to ordinary users. That's pretty much kicked off the platform. The data may be on the blockchain, but almost no one can see it.