Memory Card Data Deleted Automatically?

[SAVVY_1]

Memory Card Data Deleted

* When you download an app & give permission to allow it to "MODIFY/ DELETE SD CARD CONTENT"
Exactly what do they delete? Anything they feel like because you gave permission from the start?

* Is there a setting that prevents data on the memory card from automatically being deleted?

I have ample storage available but I believe some data i.e. general photos have been deleted, again.

I definitely know that a few months ago the phone was doing some odd things (par since that update): the phone was freezing up and a lot of photos were deleted. I attributed that to a music player application & a secondary camera app. I uninstalled the app then and haven't had a problem since.
Whether there's any validity to that I don't know.

I back up my data regularly & uninstall apps if I'm not using them.

Any comments, suggestions...?
As always, thanks for the help.