The European court said while the phrase on the placard-- "Casse-toi, pauvre con [Piss off, loser!]" -- was "offensive," it was done "in a satirical vein" politicians should expect to see, Radio France Internationale reported Thursday.
Herve Eon was arrested in 2008 for displaying the sign while then-President Nicolas Sarkozy was visiting the town of Laval. The phrase on the sign was the same Sarkozy had spoken a few months earlier to a man who refused to shake his hand.
A French court found Eon guilty of an "affront to the head of state" and gave him a suspended fine of about $40.
After a French appellate court upheld Eon's conviction, he appealed to the European court in Strasbourg.
The Strasbourg justices said Eon's punishment, even if largely symbolic, was "disproportionate" to the offense. Justices said the conviction could discourage similar satirical criticism.
While Eon and his attorney welcomed the ruling, they regretted the court did not call for the abolition of the 1881 law under which Eon was charged.