You guys agree or what?
You misunderstand. There is an explanation here.
https://bitcointalk.org/index.php?topic=458386.0Well although the problem was known before, nobody exploited it on a large scale until now. And why now?
Because Mt.Gox put it in the spotlight. I doubt more than a handful of people were aware of this before.
Because MtGox said they would not allow withdrawals until the
issue non-issue was fixed. They dug a hole and this is their way of forcing a fix so they can get out of it.
I actually think I do understand.... I read that first post, and it confirms what I said in my post above. Correct me if I'm wrong but I think I'm right.
And if I understand correctly, this is an issue where the THEIVES have to act QUICKLY.
If you wait 10-20 minutes (confirmations), then there is way too many computers, ie: the whole network with the transaction and question already confirmed and buried under other ones- can't change the hashes now. (lest you do a 51% attack, which presumably again is harder with the passage of time)