They can also load the tuners original tune back on the car if they really want to complain about it.
Locking a tune is bogus shit. i would venture that 90% of tuners DO NOT lock the ecu. How is the user going to adjust 2 step and launch control and boost control depending on the EMS being used? Especially if you payed for a nice standalone or chipped/flash EMS, now you cant even use the features you payed for that are built in because your tuner locked it?