The man was arrested after spray-painted swastikas were found on the doors of Shaar Hashomayim, one of the city's largest synagogues.

Richard Holzer, 28, pleaded guilty to attempting to stop people from exercising their religion with an explosive or fire and attempting to destroy a building used in interstate commerce in a plea deal with prosecutors.

"We learned that the posts were in fact made by an employee ... . We do not tolerate any behaviour of this kind."

Liberal MP Anthony Housefather and Conservative MP Marty Morantz are joining an international task force aimed at making web giants do more to combat anti-Semitism online.

Conservatism today isn't what Charles Adler signed up for when he first voted for the Ontario provincial and federal conservatives in the '70s, he writes.

The national director for the League of Human Rights for B'Nai Brith says they're seeing an ever-growing amount of anti-semitism on the internet.

"It's important that no matter what the intention of the organizers that those who joined with this hateful speech are held to account."

'Things like this are keeping hate alive in this world. We all need the exact opposite of that right now.'

The 'Stranger Things' star, who is Jewish, said the alleged incident took place in 1995.

"We ask Jewish community organizations to implement all possible precautions to ensure the online security of their members and we urge police to take appropriate actions when online anti-Semitic attacks occur in order to bring perpetrators to justice."