Old industries - and new ones - can be changed in a moment when new technology arrives. Competition can be affected almost before anyone has had a chance to examine it. Entire new industries can arise within an accounting year, and big names can tumble as fast - from banking and retail, to media and telecoms. How should regulators and government respond to incumbents and entrants when they both ask for help? Are the interests of the consumer being upheld or unwittingly eroded?