By the silly block on Amazon

People nowadays are paranoid more or less --- more if you're a Linux user. Luckily it's really easy to disable web cam on a kernel module level. If

lsmod | grep uvcvideo


gives you some entries, you are good just to disable uvcvideo by:

sudo modprobe -r uvcvideo


Where r stands for remove. On the other hand, if you want to make this permanent:

sudo vi /etc/modprobe.d/blacklist.conf

sudo modprobe uvcvideo