FPGAs are a very flexible and powerful tool to do safety research.

The main property of FPGA is their low latency. Communicaton lines within devices can be interfered and data transmitted over one line could be tampered. So did one user use an FPGA to listen to the i2c communication between a microcontroller and a radio chip and rewrite certain messages sent from the microcontroller to the radiochip. This way the frequencies used by the device could be reprogrammed without the need to hack and reprogramming the controll software on the microcontroller.

Examples are:

Chip Whisperer

Daisho board