Although Trojan horses and Malware wreck havoc on your computers, getting into a system IRL is one of the most effective methods to sabotage your systems. BadUSB is bad news: malware that targets the firmware in your USB port's embedded system, bypassing the OS, antivirus software and other countermeasures. Using a USB firewall could be your best defense.
USG: an open source anti-BadUSB hardware firewall for your USB port. A hardware dongle that sits between your USB port and mistrusted USB devices: it will only pass a limited set of instructions and data between the two, not including the instructions used to trigger BadUSB.
Stuxnet virus; a malicious computer worm, first identified in 2010, that targets industrial computer systems and was responsible for causing substantial damage to Iran's nuclear program. It was believed to be brought into Iran’s Natanz nuclear facility on a thumb drive by an Israeli double agent.
Russia was able to break into a classified network by distributing virus-filled USB drives at retail kiosks around NATO headquarters in Kabul. Eventually, the right employee bought one and plugged it into the system that was completely unconnected to the internet. These are few of the high profile cases of BadUSB attacks.
While not everyone is writing nuclear codes or creating military programs, an USB firewall may seem unnecessary but who hasn’t bought a cheap thumb drive in a rush. That thing could be filled with nasty software that you’ll never notice and is feeding your personal details to outside party.
This defense for cyber security is also recommended by Jamie Zawinski, a veteran programmer who has contributed to Mozilla, XEmacs, and early versions of the Navigator. Ergo USB firewall is catching on!!