Maybe you should have googled the underlining name, too..

http://www.wizards.com/Magic/TCG/Article.aspx?x=mtg/tcg/shardsofalara/spoiler

This is the "Planeshift" of Magic the Gathering.

As I've retired my duties as GM lead and stopped being involved in development as well I think it's fair to note down some ideas that I think might be helpful in future.
I have worked on a proof-of-concept for this idea in python for a while and I think it can work with some tweaking.

The problem is following:
It is hard to judge whether two characters ingame are played by the same person or not. As GM you still can check whether the IP is the same, but as player you only can judge by the way they act with factors taking into account like speed of typing, spelling errors, usage of words, inside knowledge and so on. The later also only works if you know the two characters very closely.
As GM you often don't have this close view onto these characteristics; so if someone logs in with a different char and a different IP it's near impossible to tell for sure it's the same person or not.

This issue is the same for any application with identity being a critical factor, therefor approaches to the problem also are manifold:
- using the MAC address
- using other hardware characteristics like harddrive number, CPU and such
- using unique accounts that are sold in RL
- registering accounts by creditcard number
- registering by making a payment via money transfer (paypal, etc)

Any of these measures however can be circumvented, are massively intrusive into the user's privacy and don't even tackle the issue directly - to identify the user while they use the product.

The idea now was to use what's already there: the typing of the player when they play the game.
For this all keystrokes are recorded client-side as a pair of (previous_stroke,current_stroke), which are used as keys for a dictionary to record the according timing and the number how often the combination was entered.
If the combination is entered again, the timing is adapted either by averaging or using a weighted term.
Every now and again the whole dictionary client-side is read out and put into the form of a list sorted by timing (fast combinations first). All combinations that were entered only once or few X times are left out.
This sorted list is sent to the server, where a similar list is recorded for any account and adapted each time a client reports back.
The sorted list provides a form of frequency distribution that gives insight into which combinations of keystrokes are trained best by the user, which is a unique feature which can be used to distinguish one player from another and also who is using a bot and who doesn't.

I have used python with Tkinter to make a prototype for this, which worked quite well in the first tests I ran.
To reduce the load on the server it might be possible to identify the combinations used in English most often and use this as base for the distribution and then take a discrete function to describe each user's unique typing-fingerprint (utilizing fast Fourier transformation for example).

Lazy world? Not really, but thanks

Two days ago I resigned from my duties as GM leader, now I would like to announce this to you, the players, as well.
I have started playing PS four years ago. I was active as player, then as GM, settings dev and finally GM lead.
It was a long run with many ups and downs. I found many friends and people I respect for their personality and skills.

I always tried to be just and fair as GM as I saw the position more as a mediator than a policeman who has to put evildoers into jail.
The same counted for the position as GM lead, at which I hoped to help and guide as advisor, not as much as a dictator.
As such I wanted to be an example for the GMs and make their ruling over the players a just and fair one.
Investigate and mediate, that was the base in most cases, and I think it was the right one.

As much as I liked the job and most of the people, personal problems grew while my spare time to handle them waned, so I decided it was time to move on and face new (RL) challenges.

Maybe I'll have more time now to play casually again.. or maybe not. Future will tell. 

Finally! I surely poked and prodded her long enough. 

It really is a pleasure and honour to have Kada-El back at last. Hopefully she'll stay around

Take care Neko. I wish you good luck with everything - and maybe check by from time to time?

All of that was explained ingame. Sorry to those who didn't get anything, congrats to those who got something.

Thanks to UtM and Caarrie I think everything relevant is said. If you feel mistreated for another unmentioned reason you feel is important you can contact me on IRC or via forum pm.