This is very important! Some years back I found some databases of forums via google because the backup folders were not protected at all! One was from a forum with several thousand members. Sometimes it needs no uber-skilled crook to hack a site and steal their database, even admins of large sites can be lazy and / or careless so the best thing is always to expect the worst and choose a strong password you use only for that specific site. Tools for this (KeePass and so on) have already been mentioned here.