First - forget a laptop. Use a blackberry or iphone.
Second - the sucker is not the guy betting at the game. The sucker is the idiot betting live sports at home on delay. Nothing at all wrong with gaining a legal advantage!
It has happened for years. I was sitting with a laptop and mobile phone courtside at Eastbourne for the last several years, Open Gaz de France and most other European tournaments were the same.
There is/was enough money in scooping up to make it worthwhile.