Even with a co-ordinated countdown approach, the timing with multiple people involved would be *wildly* different as compared to hardware or software boxing.

The difference might seem small to us, but the GMs would have access to server logs with high resolution timestamps and the difference - and indeed the variation in differences - will be huge when measured there.

If you were challenged though?

I've often wondered about this, especially since both my wife and I multi-boxed, and all I can imagine is that they would ask us our secret question (if they're even allowed to do that) or somesuch.

I *suspect* that if the names are similar, and the contact details pretty much match then it'd be a no-brainer for them. If they weren't the same (a friend visiting perhaps?)... I don't really know.