As a photographer, I have roughly 400GB of edited photos on my machine then have 150gb worth of music. That's what takes up 90% of my storage space. I have 3 separate external hard drive with my system as well as another 2 for RAW files and videos. Back everything up every 7-10 days for redundancy. I do keep a good number of photos in the cloud/online, but that's never my backup solution; that's mostly for making sharing easier.
As far as theft goes, I can't imagine anyone ever going through the trouble to take my computer AND my hard drives. This isn't a movie. They're not stored right next to each other so someone would have to really want them if they went to the trouble of looking for them. My biggest fear is my building burning down or an earthquake, but honestly, I'd have bigger concerns if either of those happened
As far as theft goes, I can't imagine anyone ever going through the trouble to take my computer AND my hard drives. This isn't a movie. They're not stored right next to each other so someone would have to really want them if they went to the trouble of looking for them. My biggest fear is my building burning down or an earthquake, but honestly, I'd have bigger concerns if either of those happened