That's true, moreover in the legal systems I know, prosecutors also have the authority to request such documents that means the documents requested can be used

That's true, moreover in the legal systems I know, prosecutors also have the authority to request such documents that means the documents requested can be used as evidence. If you do not comply with it a judge can compel you to give up the document. In which case you also might get in legal trouble, because you refused the initial request of the prosecutor. Furthermore, at least here in Turkey, communication records are also used in civil cases. For example, in a divorce case, the parties sometimes request the phone log through a judge and prove disloyalty by showing call history and duration of each call.