wavebreakmedia/Shutterstock.com
Nearly half of US sports bettors placed an illegal bet over the past year. It's costing state government millions in tax revenue. Online slots and unregulated machines are costing states even more.Millions of Americans placed bets on the World Cup over the past month, but many likely did so illegally. Illicit sports betting — and illegal gambling more broadly — is costing states millions in tax revenue, and someday, taxpayers could be called upon to foot...