What has changed is that legal sportsbooks are now required by law to monitor and report unusual betting activity to authorities.

After a recent N.B.A. scandal, more writers and pundits have come out against legalized betting. But the case that they’re making is weaker than it appears.

Last week NBA stars were accused of faking injuries and insider trading. This type of thing has been going on forever — the difference is, now athletes are getting caught.

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Legalized sportsbooks, and their cooperation with the NBA and law enforcement, are likely a big reason the scheme was uncovered at all.