Apple sell you an iPad. At the price they charge for them, they shouldn't be making any decisions about how you use it. Perhaps it's Apple who are being unethical by locking down iOS so tight that it's next to impossible to hack? I will not buy my ethics system from Apple, or any other manufacturer of consumer electronics. They've all lost enough lawsuits to tell me that their own methods are far from ethical.
AFAIK, iPads are not carrier-locked. iPhones are, usually, because you get them at a subsidized price, and the carrier wants to make sure they get their outstanding cash back. It is illegal to unlock an iPhone that's still in contract. That was the law that changed.