After receiving requests from UK police and the FBI in September 2009 and April 2010, Yahoo created several “snapshots” of the email account, preserving its contents at the time—and revealing the messages. But the defense alleges there should have been nothing for law enforcement to find.
Yahoo’s explanation is that the recovered emails were copies created by the email service’s “auto-save” feature, which saves data in case of a loss of connectivity, for example. The company has filed several declarations from a number of its staff, but the defense said some of those contradicted each other, and it wants more information.
The question of when, and for whom, data has been deleted or made inaccessible is often based on power and knowledge. And end-users tend to lack both.