You can just authorize to remove the data and just change the keys, or place a password.
You should have the rights over your address book, and files shared there. If things were copied after shared, that's a different story. Maybe something to block the ability to record from the screen. Then one can use a camera. Etc imagine authorizing only a device with the part number that blocks the ability to photograph what is seen on the screen, and a data can be created to execute only on the device, and it could state in advance exactly what it is asking for from the device via part number and some key generation that the camera blocking screen that is generated without a screenshot ability neither where only the human eye could view what is on the screen. Then we can just transfer the data, and just change the keys.
This means people would have to resort to somehow recreating what they see in the screen when they read the data on such a structure that only accpets the above type hardware to interact with it.
People themselves will definitely need to spend safecoin regularly when storing information, but imagine that a single safecoin would get you the equivalent of a few dropbox account or better, if only to run a node for at least a month.
Unlike dropbox etc, there is no subscription model therefore, your data is yours forever, and all new data costs safecoin as usual. pay as you go so to speak.
perhaps, a name registration with the type_tag, by providing a client interface you'll get safecoin through the application.