know your caches

It is somehow alerting how much information can be found in a cache folder. It might include personal data, such as:

a list of all your friends
email addresses from your mail program
telephone numbers if you synchronize contacts with your mobile phone
photos either from your phone, skype, facebook and where ever they get shown
which music you have on your computer
many media players automatically download cover arts and store them on your disk. Even the download must be seen critical.
passwords
some applications even cache passwords
all your personal photos and every movie you got on disk
most image viewers or filemanager will create thumbnails
visited websites
browser caches

Browser Caches

$HOME/.cache/chromium/
$HOME/.cache/mozilla/
$HOME/.cache/midori/

Remote desktop caches

$HOME/.rdesktop/cache/pstcache_2_2

IMs

$HOME/.Skype/
$HOME/.purple/[logs,icons]

thumbnails

these locations seem to be compatible (having subfolders fail, large and normal)
$HOME/.thumbnails/
$HOME/.local/share/thumbnails

Make caches be a temporary place

This will slow down your computer in some cases, but might be worth it.

max,