[SudoNick]

If I may suggest a slight rephrase: If you are concerned about RELIABLY destroying your data (which involves being able to verify for yourself that it was thoroughly destroyed when you think it was destroyed), you should keep that data on your own devices.

If your data is stored on a server that someone else controls, you can't reliably destroy that data. Even if it appears to have been destroyed immediately, there could be other copies somewhere. So wherever possible, sensitive data should not be stored on someone else's server. Even in encrypted form.