  Proof-of-work puzzles and CAPTCHAS consume enormous amounts of energy and
time. These techniques are examples of resource burning: verifiable consumption
of resources solely to convey information.
  Can these costs be eliminated? It seems unlikely since resource burning
shares similarities with "money burning" and "costly signaling", which are
foundational to game theory, biology, and economics. Can these costs be
reduced? Yes, research shows we can significantly lower the asymptotic costs of
resource burning in many different settings.
  In this paper, we survey the literature on resource burning; take positions
based on predictions of how the tool is likely to evolve; and propose several
open problems targeted at the theoretical distributed-computing research
community.
