GTech Holdings Corp, the world's biggest operator of national and state lotteries, also produces scratch and win instant lottery, has been proved a flow in Taiwan.

This is due to an error of computerized system that allows people to identify which instant lottery ticket is a winner and which is not, according to the barcode.

Taiwan has issued a complete recall of its scratch tickets, saying it is possible to discern winners from the bar codes on unscratched tickets and that it suspects outsiders already have cracked the algorithm on some scratch ticket bar codes, the report said.

A corrupt ticket salesperson that knew the codes theoretically could pick out the winners on a sheet of tickets and cash them, selling only the losers to the general public.

Gtech also told the Journal recalling the Taiwanese tickets was a decision to err on the side of caution, and added that the company didn't recommend recalls in other places.

Data from the most recent fiscal year available – ended June 30, 2001 – showed that governments sold $27.5 billion of scratch tickets worldwide, or 21.6% of $125.6 billion in total lottery sales, according to David Gale, executive director of the North American Association of State and Provincial lotteries.

A 19y/o Taiwanese man is the guy who found out the "tricks" to be instant winner. He has collected at least 10000+ tickets for his "experiments".