http://www.sportismadeforbetting.com/2011/12/its-all-gone-pete-tong-at-betfair.html
In short: Betfair is a betting exchange, where people can set their own odds and bet against each other. £20m was 'layed' against a horse @ 28/1, which would have a potential liability of £600m ($1 billion US). £1.6m of that figure was matched (£800K*27 is liable to the layer).
The clincher is that the horse was about 8 lengths in the lead when this was happening.
It would seem to be a computer/bot error from either betfair or another large gambling outfit. It seems betfair was looking around for reasons to void bets on the race. Should be an interesting outcome.
ahhh, boring result
QuoteCustomers betting in-play on this race will have seen that Voler La Vedette was available to back at 29 when the in-running market was suspended, and that a considerable sum was matched on the clear winner at that price.
An investigation has revealed that this was due to an obvious technical fault which allowed a customer to exceed their exposure limit.
In accordance with our terms and conditions, all in running bets on this race, both win and place, will be made void.
We fully appreciate the dissatisfaction this will cause many customers, and apologise for a very poor customer and betting experience.
so basically you risk your money on a bet and no guarantee of getting paid, never mind winning :)
wonder what the backlash will be though?
People have short memories. Business as usual. Such massive bets are beyond the comprehension of most people and they wont be able to relate to it.