The problem of distinguishing between "problem" and "non-problem" gambling revenue cannot be solved by gamblers themselves. The Government should give Mr. Fischer the tools he needs, modelled on the way banks act in their self-interest to stop us over-extending ourselves on credit.
Firstly, we need to eliminate cash from the gambling industry and replace it with a plastic card. Not only will this give self-exclusion teeth, it will link each wager with an individual. Secondly, we need information-sharing between gambling providers akin to the credit industry: before a wager is offered the provider would know the betting history of the punter along with other financial information available to credit card companies.
Then the gambling operators must be prepared to defend in court their decision to offer wagers without the defence of "we didn't know". They will have to turn away and report punters who have embezzled and gambled away amounts far in excess of their salaries. Similarly, they will be forced to have a policy on taking money from low-income gamblers.
Would Mr. Fischer and his colleagues knowingly and publicly accept bets amounting to 50% of the discretionary income of a pensioner?