WOAH! Do not put symlinks to your uploaded files in a temporary cache directory. Nginx users running WordPress should beware if they followed these instructions and put a symlink to uploaded files in the wp-content/cache/ directory. I’m going to rewrite that page right now suggesting they use a different directory, possibly wp-content/uploads/ or maybe wp-content/files/.
WP Super Cache (and I presume other caching plugins) will delete everything in the cache directory. It’s like putting important files in /tmp/ where files are routinely cleaned out on reboot.
My replies on the thread above might paint me as a cold heartless bastard but I am sorry those websites suffered data loss. However I’m shocked that they put links to uploaded images in a folder containing temporary files!