Its kind of cheesy, but you can use .filename or put spaces in the filename or leading spaces to make hard on those who don't know how to handle that. Like a leading space in a filename that will stop most people.
touch " filename"
touch ". filename"
ls filename won't work. You must do ls " filename" or ls ". filename" to ls the file.
Same with vi. If they try to vi . filename, vi will try to open the directory as a file and a file called "filename". 2 files!
ONE CAVEAT HERE...
However, in my environment. I as root have cron jobs that search for and report an files with weird filenames.
So you can't stop root from finding or accessing them. Maybe these tactics will stop some from looking at your file. Although, it kind of like locking your car doors with the window rolled down!
Try it and report back.
