In early Memrise days, year ago, there was a public global leaderboard. There were so many complaints about hacking and cheating, that Memrise decided to hide the leaderboard.
Later (2012?) community members liked the idea of a top-50 list, and began assembling the list in a thread in the community forum. Members on the forum proposed names and the number of points they had. By consensus, the top-50 list as built in the forum excluded certain members whose scores didn’t seem to represent whatever the forum participants wanted.
That hand-maintained list worked well for a couple months, then Memrise staff (Ben?) posted the link to the top-secret global leader board.
Ever since then, that list was alway labeled “top secret”, and I don’t recall it ever being touted by Memrise. I would imagine it’s probably still out there somewhere.