Apple, Google, Facebook, Twitter and four other American Internet rivals have teamed up to tell the U.S. it's gone too far. They're demanding in an open letter that the government curb its massive collection of personal data.

They've got a business reason for doing so. Many web companies warn they'll lose revenue overseas. Forrester Research estimates cloud computing companies could lose $180 billion by 2016. On a smaller scale, the Information Technology & Innovation Foundation estimates they could lose up to $35 billion to European and Asian rivals.

The public campaign by the co-signers also includes the launch of the website, reformgovernmentsurveillance.com.

The UK-based civil liberties group, Big Brother Watch welcomed the move, saying surveillance laws in many countries including Britain and the U.S. were no longer fit for the Internet age.