Android :: Files - Local Files - Storage

From the Android documentation:

"You can store files directly on the mobile device or on a removable storage medium. By default, other applications cannot access these files. "

I could write to the sdcard (/sdcard/file.tmp) and other apps could access these files, right?

I would like some local storage that I can write files to (and read from later) that are not accessible to other applications, and I will always have access to. The problem with the sdcard is that if someone plugs in a USB cable and turns on MSC, my application (and all applications on the phone) will lose (both read and write) access to the /sdcard directory. So I need something more reliable.