It (apparently) is not a myth that by the time the Thames has got to London, the water extracted from, to turn into drinking water, it has already been through an average of seven other people. And, whilst there is a reverse osmosis plant on the Thames Estuary, it is only used during times of drought and then to turn brackish (salty) estuary water into drinking water. Normal water treatment plants use traditional methods such as sand and/or trickle beds + UV purification. Reverse Osmosis is otherwise waaaaaaay too expensive.
Er.. most of the exploits are only possible if one is root and/or the directory is writable for some other user (e.g. leon in this case).
Since one is root, one can do anything anyway so why bother with all this misdirection? If someone leaves world writable directories lying around (especially without the sticky bit set), then they deserve everything they get. Or is this some kind of "trap the (completely) unwary sysadmin" wake up call? If I see some strange named file (especially if I know I didn't put it there) I would investigate very, very carefully what is going on. I can't be alone in this - surely?
The Health Service is creaking a bit though...