Backing up the entire website?

Backing up the entire website?

I would like to make a backup of all the art that has been submitted to this website. I have a feeling though that if I start using a script to download everything, it would possibly result in an IP ban or be highly frowned up due to the extra bandwidth costs. Any suggestions on how I could go about doing this? I've learned that if you don't back things up now, you'll regret it later. I estimate it will be around 1 terabyte of data or less for all the art assets.