Having your terminal session stored on disk mean that everything you see is suddenly on your filesystem, and staying on it if your /tmp is backed by the harddrive.

No. If you open(O_CREAT) a file than immediately unlink it, and use the opened handle to store temporary data, that data has no more chance to hit the disk than regular memory being swapped out.

Try to learn a bit about buffer cache and such stuff.

This "bug" is about someone ignorant about security and how an OS works having his naive assumptions contradicted by reality.

This really sounds like how it was designed to work.

Thats what /tmp is for, after all, is it not? Sounds like the problem would be solved by partitioning different users data into seperate, appropriately secured /tmp files.

Is bash history a "flaw" too? I'm sure plenty of people don't know that it's a text file anybody with access to it can read.

with the exception of the list of games I've bought (oh, no!)

Any PS3 games that will not play on the 360? Or maybe just quit consoles and try computer gaming again. Haven't touched a computer game since the 32-bit Amiga era.