The United States has arrested a second Internet gaming executive, adding to fears it is cracking down on the lucrative industry and sparking share price falls on Thursday that wiped over USD 1.5 billion off the market value of the sector. Online bookmaker Sportingbet Plc said its chairman, Peter Dicks, had been detained by U.S. authorities, mirroring the detention in July of another online gaming CEO on racketeering charges.