Microsoft is suing the Department of Justice (DoJ) to protest the gag order that prevents technology companies from telling their customers when their cloud data is handed over to authorities.https://mscorpmedia.azureedge.net/mscorpmedia/2016/04/ECPA-Complaint.pdf
In layman's terms, the Electronic Communications Privacy Act (ECPA) allows the government to issue gag orders saying that the people or companies involved in a legal case cannot talk about the case or anything related to it in public.
So, the government is continuously forcing tech companies to hand over their customers’ emails or personal records stored in the cloud servers without their clients' knowledge.
Microsoft has filed a lawsuit [PDF] against the DoJ, arguing that it is "unconstitutional" and violates constitutional protection of free speech to force the tech companies for not informing their customers when their stored data has been shared with authorities.
According to Microsoft, the company has received nearly 2,600 gag orders in the past 18 months. Though the issue is not with the concept of government searches, but with the indefinite period of those orders.
Transparency is good for everyone and those suspected of terrorism etc wont really be watching the MS site for any cloud data farming notifications of that I am sure, however there can be cases where its prudent to delay such news to assist law enforcement and that sort of request will no doubt still be respected.