The 74-year-old former local councillor was apprehended outside David Jones in Barangaroo last Friday, while holding a sign that read: "SMILE CVN'T! WHY CVN'T?"

Video of the arrest was posted on social media with one clip on Facebook getting 1.3 million views, while hundreds protested in support outside a Sydney police station last Sunday.

It's understood at least two people have made formal complaints about the use of force by police during the arrest.

Mr Lim is a regular sight on Sydney street corners carrying signs with political and social messages.

His lawyer Bryan Wrench confirmed his client will be challenging the fine and is awaiting a court date.

He is also considering taking legal action over the manner in which he was restrained, once the other matter is finalised.

"It just appears unjustified," Mr Wrench told AAP.

The lawyer compared the case to that of teenager Jamie Jackson Reed, who was awarded nearly $40,000 in costs after his forceful arrest at Mardi Gras in 2013.

"If we didn't have video of it, it's a much harder case to run," he said.

In August 2017, a NSW District Court judge overturned Mr Lim's earlier conviction and $500 fine after finding a sign worn in 2015 mocking then-prime minister Tony Abbott was poor taste but unlikely to offend the average Australian.

Using an inverted A in the word "can't", those signs said: "TONY YOU CAN'T. LIAR, HEARTLESS, CRUEL" and "TONY YOU CAN'T SCREW EDUCATION."

Australian Associated Press