Prediction markets like Kalshi and Polymarket have an insider-trading problem. And now it seems the U.S. Department of Justice is doing something about this illegal activity. Last month, the DOJ charged a U.S. Army soldier with profiting from Polymarket trades made using their access to classified information regarding the capture of Nicolás Maduro in Venezuela. Now, the DOJ has made another insider trading charge. This time against an engineer at Google. According to the  DOJ complaint , Google engineer Michele Spagnuolo made more than $1.2 million off of Polymarket trades based on the search giant's confidential business information. "Today’s charges reinforce a decades-old message: corporate insiders cannot use confidential business information to turn a profit in our markets,” U.S. Attorney Jay Clayton said in a statement.…