Just wondering about the mechanics of account Mist Energy sharing.

From what I've read on the forums and the wiki,

1.Accounts that use the same computer share mist energy.
2.Paid accounts are exempt.
3.Mist energy for shared account is the lower of the two.

How does this work?
Does the sever remember your IP? your MAC? your computer name? your spiral knights local installation?
(does it apply across shared network, different OS, different OS user, reinstallation of game)

Is this "sharing" applied when you log on (mist energy deducted to lower of logged on accounts), or does the sever remember the accounts that are shared?

If for example, you walk a friend through registration and a few levels on your computer, (which you normally play on) and later on, he/she plays at home. Do you lose any Mist Energy?

Or really complicated:
if account A normally logs on at computer A,
account B logs on at computer A and uses mist energy (say from 100 to 50),
B goes home, logs on at computer B, uses more mist energy (say to 0).
When account A logs on at computer A, how much mist energy will account A have?

100? 50? 0?

(don't tell me the correct answer is "get a paid account")