Quote from: jackofspades on April 02, 2013, 05:35:54 PM

where did the original 6 confirmations needed come from anyway?!
is it just an arbitrary number?

From the wiki:

Quote

Merchants and exchanges who accept bitcoins as payment can set their own threshold as to how many confirmations are required until funds can be considered valid. When potential loss due to double spending as nominal, as with very inexpensive or non-fungible items, payments can be considered confirmed as soon as it is seen on the network.

- http://en.bitcoin.it/wiki/Confirmation

A digital currency exchange that sends out non-reversible funds when there is no recourse (i.e., withdrawn by an anonymous user) should not be considering anything less than 6 confirmations, in my opinion.

Of course, those funds in their wallet are not theirs (as they are customer's funds), so they can be careless without exposing themselves to the risk.