SOFTWARE WRITE BLOCKING

Just as hardware routers are really just pretty boxes running software routers (usually on Linux), hardware write blockers are almost always small computer devices running write blocking software. There are several commercial options for Windows systems. Naturally, most of the Linux choices are free and open source.

There is a kernel patch available to mount block devices automatically. You can also set something up in your favorite scripting language. Next I will describe a simple way to block anything connected via USB using udev rules.