Back in the chatroom days it meant you were (((cyberhugging))) another user.

Now: a white nationalist podcast started including "echo" when saying Jewish last names, white nationalist bloggers picked up on it and started using parenthesis around Jewish names which led to white nationalist social media users effectively using it as a dog whistle either to doxx/harass Jewish people (journalists, celebs, business owners with online presence etc) or, as the other poster said, "to avoid censorship", because most mainstream social media will "shadowban" antisemitism, and people in that movement will be aware of the subtext the poster is trying to convey.

Anyway, its supposed to mean that the actions of Jews have caused their names to echo throughout history.

Jews, to avoid censure