No "thank you"s unless you've won.

[EDIT]
Instead, tell me about a memorable event that you witnessed or experienced during a multiplayer game, if you have one.

[EDIT 2]
I used to play Final Fantasy XIV: A Realm Reborn. I mained a White Mage, and was doing my daily roulettes, and I got dropped into Hard Mode Titan. I wasn't that concerned, because HM Titan was the boss battle that I saw most often, so I had his patterns practically memorized. Everyone readies up, main tank pulls, then on the first moment that Titan can knock someone off the platform we're fighting on to their impossible to resurrect from doom, one of our DPS fails to dodge and dies. Then when the arena is about to shrink via the outer edge dropping off, along with anyone standing on it, the main tank lags for a moment, doesn't get out of the danger zone in time, and falls to their doom. Off-tank pulls, starts dying much faster than the main tank had been, the other healer and I start casting on them immediately. Off-tank loses aggro to the other healer almost instantly; other healer dies, then I die next, then the rest of the party wipes. I figure that aggro was lost because they didn't use the abilities needed to keep it, and I decide to check the off-tank's gear and stats to figure out why they were taking so much damage so fast, and I find that they are wearing crafting gear instead of their actual tanking class gear. When I point it out and ask why, the answer I get is "Because I didn't want to main tank XD"

Needless to say, I was very unimpressed with that.