Many people have given great suggestions for the most destroying commands, but most result in an immediately borked system. While inconvenient, that doesn't have a lasting impact on users who have backups.
I propose writing a bash script set up to run daily in cron, which picks a random file in the user's home directory tree and randomizes just a few bytes of data in the file. The script doesn't immediately damage the basic OS functionality, and the data degradation is so slow that by the time the user realizes something fishy is going on a lot of their documents, media, and hopefully a few months worth of backups will have been corrupted.
Everyone is talking about rm -rf / and damage to storage drives, but I read somewhere about EFI variables having something to do with bricking the computer. If this is possible, then it's a lot more damage than just disk drives.
"wipefs -a" instantly removes filesystem signatures. It's fast, doesn't actually delete data but is just as effective in most cases where you're not worried about someone trying to recover it. Much faster than rm on /. As far as the OS is concerned the drive is then empty.
I don't know about how exactly to do it, but I do have an idea or two.
Something that will reflash the firmware on as many devices as possible using garbage data. At least the UEFI.
Filling most of the drive space, leaving let's say 50MB, then overwriting those 50MB repeatedly to damage the hardware itself. I suppose you could do the same with RAM. If we're dealing with PMR/CMR HDD, then you should just be able to write to specific sectors without doing it by filling the rest.
If present, keep ejecting the DVD drive. Either the mechanism dies or someone accidentally bumps into the open tray and breaks it off.
Keep hard rebooting the laptop after some time. It may corrupt some data, and put the blame on hardware. The hard reboot can be done by echo b > /proc/sysrq-trigger This will need magic SysRq compiled into the kernel, and power off/reboot enabled. The latter can be done by enabling all magic SysRq functions echo 1 > /proc/sys/kernel/sysrq or just reboot/power off with "128".
dd if=/dev/urandom of=/dev/sdx will overwrite every single byte of /dev/sdx with random data. Replace /dev/sdx with the drive you want to wipe. Optionally, specify a larger block size to speed it up more.
Modern disks have encryption enabled in disk level. This will change the encryption key on the disk, meaning that in seconds all data in the disk is in unrecoverable state.
This is way better than writing the whole disk 0's or rm -fr /
I was a newbie user, telling a friend of mine about rm -rf /*. I typed it in a hit Enter, telling him it doesn't harm since I didn't enter sudo. But I'd forgotten that I have still permission to delete my home directory. 🥲😂