The large companies obviously know how to avoid accountability by eliminating, or never creating paper trails.

Unfortunately it doesn't seem that it was a lack of a paper trail that kept the principals of HSBC out of orange pajamas. But rather an apparent perception on the part of the government that they were essentially beholden to HSBC for the sake of, well, it's hard to say precisely (but you can chose whether you want to take the AG's concern about "jobs" at face value or not):

  In December 2012, Assistant U.S. Attorney General Lanny
  Breuer suggested that the U.S. government might resist
  criminal prosecution of HSBC which could lead to the loss
  of the bank's U.S. charter. He stated, "Our goal here
  is not to bring HSBC down, it's not to cause a systemic
  effect on the economy, it's not for people to lose
  thousands of jobs."

Source: http://money.cnn.com/2012/12/12/news/companies/hsbc-money-la...

See also: http://www.theguardian.com/business/2013/may/30/treasury-dep...