When the Unlawful Internet Gambling Enforcement Act (UIGEA) was passed in 2006 a lot of the foreign gaming companies left the US market. Even though the law only came into effect in June of 2010, most companies with listings in the London Stock Exchange pulled out of the market when the law was signed.
One of those companies was Sportingbet, the company had legal trouble with the US before 2006 and they have been negotiating with them for the past couple of years. The violation that Sportingbet is accused of is taking bets on casino games from US citizens.
However, the company has announced that they have finally reached a settlement with the US and it allows Sportingbet to avoid prosecution and perhaps even re-entering the US market in the near future, depending on legislation changes.
The company has agreed to pay $33 million to the US and they are probably happy because the legal prosecution had kept investors away, but after the announcement their stock immediately went up.