I have just started to learn the GNUstep's development environment and I have in my very first program stumbled across a serious security problem in the way Objective-C handles IO. Obviously, Objective-C does not honour Unix file permissions. You can reproduce this problem on Unix/Linux systems by setting {{ chmod 000 /some/dir/your.data }}, and then run the example program in the GNUstep documentation page (Base Programming Manual/The Objective-C Language) under "2.8.5 Loading and Saving Strings" by setting the path to {{ /some/dir/your.data }}.