The US government’s chief antirust prosecutor Joel Klein has been talking about the prospects of a new antitrust case against Microsoft Corp by telling a business forum on Friday that the company like any corporation, would benefit from strong domestic competition. He also said, responding to a question about whether the speed of change in the high tech industry presented a special set of problems for any antitrust investigation, I will not let complexity deter me from engagement, according to Bloomberg. The opinion of the investment community flip-flopped Friday compared to the previous day. The shares closed up $2.375 at $85.75. A lot of stocks finished higher Friday driven by reassuring payroll data from the government that many took as a sign that interest will remain stable for the foreseeable future. But Microsoft’s trading volume was almost double its average, which indicates it was being singled out for special treatment.