Tensions between members of the Hasidic community in Outremont and some of their non-Jewish neighbours played out in a Montreal courthouse Monday.

Writer Pierre Lacerte has spent a decade obsessing his Outremont neighbor, Michael Rosenberg, a wealthy real-estate mogul who lives on his street.

Lacerte runs a blog in which he posts photos of Rosenberg, purportedly showing him parking illegally, or traffic jams near the local synagogue, or other perceived infractions of Outremont bylaws.

It's all part of a longstanding quarrel Lacerte has with Outremont's Hasidic community.

Tired of it, Rosenberg filed a $375,000 defamation suit against Lacerte.

“Defamation, breach of privacy,” said Rosenberg’s lawyer, Julius Grey. “While the other side is claiming abuse of procedures.”

Last year, Rosenberg failed in an attempt to obtain a restraining order against his neighbor.

Now Rosenberg complains that Lacerte's blog is costing him business -- though he wasn't able to provide evidence in court Monday.

On his blog Monday morning, Lacerte posted a caricature of Rosenberg as a Godzilla and himself as a Lilliputian. At the courthouse, he tried to taunt Rosenberg’s supporters.

The relationship between the Hasidic community and its neighbours has never been an easy one in Outremont, but this current fight goes beyond anything ever seen before: Both sides have spent huge amounts of money, taken up precious time from the courts, and increased tension within the community. 

Rosenberg openly describes Lacerte as anti-Semitic.

Lacerte denies being anti-Semitic, and claims Rosenberg has the definition all wrong.

The trial will last all week.