I've just lost all of my most important files from my computer. Not in trash, not anywhere else.
What is your rclone version (output from rclone version)
Which OS you are using and how many bits (eg Windows 7, 64 bit)
Linux 64 bit
Which cloud storage system are you using? (eg Google Drive)
rclone sync GoogleDrive:documents .
Yes, I tried to sync a Google Drive folder locally, and assumed the above command would save the folder to my home folder, rather than replace the entire content. Really, you think it's a good idea to run destructive operations without warning?
Yes that is exactly what happened and this is purely bad software design. The default should be a warning message that can be turned off using the config. It's incredible that you expect users to know flags for dry-running commands.
I understand why you're angry, and I'm sorry for your losses, but this isn't the fault of the developer, this is you misunderstanding what the term "synchronize" means, not reading the documentation, and not having adequate backups.
I agree that perhaps there should be more warnings involved when doing a potentially destructive action, but this is like blaming the developer of rm when you run rm -rf /. There is only so much handholding a developer can do, and sync is working as intended here.
Anyway, if you're looking to recover your local data, it should be possible with testdisk, as thankfully you didn't try to sync the other way around and nuke GDrive. Rclone does an OS-level delete for local files, so they should be recoverable as long as you haven't overwritten that part of the disk, albeit with possibly broken filenames. I'm happy to try and give you a hand with recovery if you like, since I know how much losing data sucks.