This is also happening on the 24 mustangs, they locked down the PCM and if you try to tune it, it will phone home to the mothership and compare itself with the as built data, and if it finds a different tune, it will brick itself. GM is also trying to prevent any tuning. It all stems from the government crackdown on illegal modifications and the only way for the manufacturers to comply with their ever increasing standards is to keep you from doing anything to you vehicle except drive it.
Right now the only mod you can do on a 24 mustang is a whipple supercharger because Ford gave them a custom tune to make it work together.