This guy came onto my server using 1 account at first, and was floating around (via World of Minecraft client) and checking everything out. A 2nd character under the same IP then came on. Immediately, I questioned them about the same IP.

Their answer was "Oh, we're at the same hotel, under the same WiFi". Then they started griefing all the pixel art on my main map. So I banned them, both the usernames and what I thought was their IP (I was off by one number).

20 minutes later, a 3rd guy popped on, and I got the login message, along with:
"Lately known as: <First username>, <2nd username>".

I immediately kickbanned and banned the right IP this time. So I figured I'd let you guys know about these 3 guys (probably 1 guy using multiple clients) so you can add their names to the spec list.

11l1ll1l1ll1l11l
1l53mfj_3r2
daav0

All 3 were using the World of Minecraft client. And incase anyone here wants to pre-emptively ban these guys from their server (they griefed pretty fast), here's their IP:  12.5.152.114

As I said in the topic title, I know this isn't something you guys normally do, Spectating griefers who haven't griefed World of Minecraft, but I think you should put these 3 names on the Spectator list as they had use of the World of Minecraft client.