Why is this needed? Occasionally, players have been frustrated by another player for various reasons: mainly because they're being rude or abusive, or at times because they appear to have left the game (and the computer is playing for them).
In these cases, it would be pleasant to have a way to boot such an antisocial player from the game, and hope that someone better joins the table.
That's what the "kick player" feature is about. If a majority of players vote to kick a player off the table, that player gets ejected! So if there are two human players at a table, a single vote will cause the player to be kicked. If there are three or four players, it takes two votes.
Voting to kick a player has a side effect. The player that you voted to kick is added to your list of "disliked players." The site will never seat you with these players again. If you wish to "undo" the effect of kicking a player, it's simple. Click on your user name in the upper right corner, and scroll down to the "Manage Dislikes" area. There, you'll see a list of all the players that you've kicked. Just click the "(remove)" link next to the player's name, and the system will forget that you ever disliked this player, so you may be seated with them in the future.
The screenshot above shows how it works. Guest #81 at the bottom hovered the cursor over the cogwheel graphic next to Guest #2. This causes a tool tip to be displayed which says "kick player?" Next, Guest #81 clicked on the cogwheel, causing a button to appear in the lower left corner, just above the chat button, labeled with "Kick Guest #2". When this button is clicked, it is registered as a vote to kick the player from the game. In a two-player game, the player is immediately ejected.
Again, if you kicked someone by mistake, and want to undo this action, go to the "Manage Dislikes" area of your profile and click the "(remove)" link. See the screenshot below:
To get to this area, click on your user name, which opens your settings panel. Below that you will see the "Manage Dislikes" area, with a list of players that you've voted to kick. Any players you want to "forgive" can be removed from the list here. You may have to use a scrollbar to view your "Manage Dislikes" area, depending on how many options show up in the profile area.
Let me know how you feel about this new feature in the comments. I hope it helps in the rare cases when it's necessary.