Only when the law is strict will people not dare to act with reckless confidence.
Tips
history
From 《左传·僖公二十六年》: 室如悬罄,野无青草,何恃而不恐 — 'the house is as empty as a hanging chime and the fields have no green grass; what have we to rely on that we should not fear?' The phrase 有恃无恐 flips this rhetorical question into a declarative.
usage
Strongly pejorative: the 'backing' is typically power, wealth, or connections being abused. The person is arrogant, not merely confident.