"So Obama has thrown in his lot with Silicon Valley paymasters who threaten all software creators with piracy, plain thievery," he wrote in a series of five tweets, accusing Google of hosting pirated material and selling advertising against it.

Reacting to the plans being watered down, Mr Murdoch wrote: "So Obama has thrown in his lot with Silicon Valley paymasters who threaten all software creators with piracy, plain thievery."

So Obama has thrown in his lot with Silicon Valley paymasters who threaten all software creators with piracy.