There’s an old tech-support joke about important data. Tech: Does this drive have important data on it? Customer: Thanks for asking, it does indeed. Tech: Good. I’ll erase it now. Customer: Nooo! I’ll loose everything! Tech: If it’s that important, you’ll have a backup. Customer: What’s a backup? In short, if it’s on a computer and it’s important, there should always be a backup. We’ve gotten better about this. Dropbox was the first service to really break through the noise about backups.