"What a shame. This is not France," declared Guillaume Garot, a former Socialist MP and Bonnefont's political opponent.
"Next year the cages will be electrified," one commentator quipped on Twitter, next to a picture of Bonnefont, whose swift political rise has earned him comparisons with Nicolas Sarkozy, the tough-talking former French president.
Now the mayor has hastily ordered the cages to be "temporarily" removed, saying they would return soon filled with pebbles to reflect the square's "mineral aesthetics".
"I regret the works started on Christmas Eve," he conceded.
London mayor Boris Johnson was dragged into a similar controversy earlier this year. A luxury development in Southwark installed anti-tramp spikes near the entrance, prompting the mayor to intervene and demand their removal.
-The Daily Telegraph