The U.S. Supreme Court case Jones v. Bock, Warden et al., 2006 revolved around the interpretation of the Prison Litigation Reform Act (PLRA). The PLRA requires prisoners to exhaust all available administrative remedies before filing a lawsuit about prison conditions. In this case, three Michigan inmates filed lawsuits without fully completing their prisons' grievance procedures and had their cases dismissed by lower courts as they hadn't exhausted all internal avenues for resolution first. However, in a unanimous decision led by Chief Justice John Roberts, the Supreme Court ruled that failure to exhaust is an affirmative defense that must be pleaded and proven by defendants rather than an absolute prerequisite for litigation imposed on plaintiffs at outset of legal proceedings. This meant that while prisoners are still required to go through internal complaint processes before suing over prison conditions under PLRA rules, it's up to defendants (in these cases typically prison officials) not judges or court clerks to raise and prove non-exhaustion in order for such suits to be thrown out.

In the dissenting opinion for Jones v. Bock, Warden et al., Justice Thomas, joined by Justice Scalia and partially by Chief Justice Roberts, argued that the majority's decision to eliminate the total exhaustion requirement in prisoner litigation cases was a departure from established precedent. They contended that this change would lead to an increase in frivolous lawsuits filed by prisoners and put an unnecessary burden on federal courts. The dissenters believed that requiring prisoners to fully exhaust their administrative remedies before filing a lawsuit is not only consistent with statutory language but also serves important policy objectives such as reducing prison violence and improving prison administration. They further criticized the majority's interpretation of "available" administrative remedies as overly broad and inconsistent with previous rulings.