New Scientist said:
Every move we make online leaves a trace. This is a lesson former CIA director David Petraeus and his lover, Paula Broadwell, learned in dramatic fashion a few weeks ago after an FBI investigation – begun in response to an unrelated complaint – found email records of their illicit affair.
Such troubles may seem far from the day-to-day concerns of the average internet user. But federal government searches of user data have been growing rapidly. Last week, Google released its biannual transparency report, which shows that the US government made nearly 8,000 requests for data on its users' accounts over the past six months – one third more than the previous reporting period. Of those requests, 90 per cent were fully or partially complied with.
The search giant is far from alone. Facebook, Amazon, Yahoo and a host of similar sites all store huge amounts of our personal data. In the US, where many of the biggest internet firms are based, such data are protected under the Stored Communications Act. Law enforcement agencies require a search warrant to gain access to personal online content, just as they would if they wanted to search your home.