Internet gambling goes live in New Jersey on Tuesday. It’s the biggest expansion of the casino business in the state since the 1970s. For gamblers with addiction problems, the process of tapping a paycheck and maxing out a credit card has just become infinitely easier. . . . Defenders insist that the casinos will monitor online activity and offer help to gamblers spinning out of control, but no law requires them to do that. And with Internet gambling legalized by Nevada and Delaware this year, and bills pending in California, Massachusetts and six other states, the prospect of many thousands more addicted gamblers is a dismal certainty.