The problem is that an NSA spy named John Doe
could work for anyone and you would not know it. It's more likely that if they were going to spy on you, they'd use someone with a name you don't know, maybe 20 names you don't know, and wherever they sent them in, those that run the service wouldn't know it either.
Did you know the name Ed Snowden before he came forward and spilled the beans? I didn't. But the fact remains that he was spying for the NSA.
They could have a spy working at the supermarket where you shop, spying on customer purchasing data, connected to actual names through the use of those little loyalty/discount cards. They could have a spy working at your local library. They could have a spy working for your employer. How would you know if they did or didn't?
I think the more important issue is how comfortable you feel storing your data anywhere, not just on those servers in which you know you can access backups that linger, like Dropbox.
No matter where you store it, there will be backups. No matter where you store it, there could be a spy.
I am not saying this to make anyone paranoid, just stating a reality that has existed for a very long time.
I think about the only highly popular internet service that can be confirmed not to have kept backups of their users' data was Ma.gnolia
. And we know how that turned out. But even they could have had a spy working there, while they were still running, and none of us would have known it, and even those that ran Ma.gnolia wouldn't have known it.
So, you are either going to live your life afraid of the Boogey Man everywhere you turn. Or you are just going to live your life and only worry about confirmed Boogey Man sightings. And the Boogey man's name isn't Condaleezza Rice. The last big confirmed Boogey Man sighting, the name was Ed Snowden.