Running the gauntlet

Not to be confused with the phrase "run the gamut".
Gauntlet in Russia, 1845

To run the gauntlet means to take part in a form of corporal punishment in which the party judged guilty is forced to run between two rows of soldiers, who strike out and attack them with sticks or other weapons.

Metaphorically, this expression is also used to convey a public trial that one must overcome.