Microsoft has sued the US Department of Justice over the government’s insistence that tech companies not disclose to customers that their cloud data has been searched. The grounds would seem to be the Fourth Amendment. There is a front page story by Jay Greene and Devlin Barrett Friday April 15, 2016 here.
Brad Smith, legal counsel for Microsoft, has an official blog posting explaining the company’s position which is principled in a way that reminds one of Tim Cook dealing with breaking Apple encryption, calling it “software cancer”.
The government would probably search cloud backups for evidence of terror plots or for evidence in some criminal investigations, possibly including child pornography (where it would seem possible to scan images for matches to the database from the Center for Missing and Exploited Children). The searches could happen with any company (like Apple, Mozy, Carbonite).
Although this seems rather far-fetched right now, it would seem feasible to scan for piracy or copyright infringement (even copies of material that have not been distributed publicly).