You asked if there were any cases of someone getting hassled for modding their own gear (and outside of phones, there are plenty of examples of that happening).

You asked if there were any cases of someone getting hassled for modding their own gear (and outside of phones, there are plenty of examples of that happening). If we're going back to phones, then it would have been illegal to jailbreak for a few months in 2014 after their anti-circumvention exemption expired and before the aforementioned Unlocking Consumer Choice act took effect. Though jailbreaking is still just one aspect of how DMCA is being used to restrict what you can do with the hardware you've purchased.