[bls]

If I find your application useless then I don't want you to retain any information about me.

[steve]

welcome to the internet.

[amichail]

What if you accidentally uninstall my app and lose many hours of work?

[bls]

I understand what you mean. But, who is going to be entering valuable, unreproducible data into Facebook? If they re-install your app then they will probably be pretty happy to enter everything all over again.