Is there any file system - or monitoring tool - which logs which users have read and written which files?
Something like this:
2014-01-21 13:45:45 john 12939 /users/john/hello.txt write
2014-01-21 13:45:55 paul 12939 /users/john/hello.txt read
This should be restrictable to certain folders (only user files are interesting, not system files).