There is always the good and the bad wherever you go.
The same thing with Linux commands, there are good commands and bad commands as well.
When It comes to bad commands, we find that, the most Linux users who have executed them are newbies who was given wrong directions as help.
Note : don’t try to run those commands in your real machine, use Virtualbox if you love testing things.
I’m sure there are others commands which can be used against us.
These commands which I’m going to show are mostly found in forums where a lot of newbies are seeking for help and other online websites targeted at Linux users.
The command above will delete and erase all Data from the hard disk and format it to ext3.
mv ~ /dev/null
Delete and erase all Data from your root directory by moving them to not a valid directory.
rm -fr /
It is well known command and simplest too. It recursively remove all files from the root.
mv /home/* /dev/null
Moves all home directories to unknown location /dev/null, which means, the home directories with all Its content will be erased.
chmod -R 777 /
This will not cause a physical harm, but It will drive to low security by granting read, write and execute rights on every file to every user on that system.