Locals were furious about it, describing it as "the nanny state gone crazy", news.com.au reported.
"What an absolute whinger and loser," one Manly resident told A Current Affair.
"Really, I mean, we're all going to walk around with tapes on our mouths? It's just ridiculous," said another.
"I'm just wondering as a ratepayer how much of my money it costs to put that sign there."
One local, Martijn Timmer, took to Facebook to complain about the sign. He wrote: "Australia today. What sad people we share the land with."
The comments section was filled with disgruntled locals slamming the council's decision.
"After a few days in Amsterdam you realise how uptight Sydney has become! No tolerance for anything these days," said Dan Mulhern.
"Ruin the beautiful landscape with an ugly sign. Good one council," wrote Jane Lester.
Mike Smith added: "That image sums up modern Australia, or at least modern Sydney. Don't let your kids/dogs enjoy the beach so the rich b*****ds with Harbourview homes are not disturbed."
The council has since pulled down the sign, saying it fears retribution against the resident who made the complaint.
Sydney, you're straight-up ridiculous at the best of times — but at least that's one less bit of nanny-stating in this great city.