Who owns your tools and toys? You may have paid for them, but under the 1998 DMCA it's often illegal for you to make changes to the stuff you bought.
Right now the U.S. Copyright Office is deciding whether Americans will be able to unlock phones and other devices they've paid for, whether farmers can repair their own tractors and whether Americans with disabilities will be able to access e-books and other electronic media.
And the way things stand at present, it's necessary to return to the feds every three years to prove to their satisfaction that there's good reason to renew an already-approved exemption from DMCA. That's why, even though it's presently perfectly legal to jailbreak your smartphone so that you can switch to another network provider, for example, the feds are presently deciding whether or not to extend that particular exemption.
In 2012, the feds recriminalized jailbreaking by refusing to renew the exemption. Congress ended up having to get involved to ensure that you still have that freedom.
Oregon Senator Ron Wyden believes that this is an onerous and unnecessarily burdensome approach that stifles innovation in addition to hurting both consumers and businesses (although some businesses, such as John Deere, have profited greatly - on many of their tractors, a blown sensor shuts the machine down and idles both it and the farmer for several days until a new sensor can be installed by a tractor technician). Wyden's introduced a bill that automatically renews DMCA exemptions unless the Copyright Office demonstrates that circumstances have changed sufficiently that reimposition is warranted.