The Gold Coast City Council will be offering free wi-fi to visitors at next month's Commonwealth Games, but people using Facebook to log in to the service will have their data mined by council for tourism marketing.

The council has spent more than $5 million laying fibre cables so it can offer high-speed internet to visitors in parts of Surfers Paradise, Broadbeach and Southport during the Games.

The high-speed wi-fi option will require users to log on through their Facebook account.

A second option, which provides slower internet access with less available data, can be accessed by providing a username and email address.

Gold Coast Mayor Tom Tate said council would be using the data it collects through Facebook to help future tourism campaigns.

"We will be able to monitor the people, where they come from that is the percentage of tourists coming from China, Japan, South-East Asia and locals," he said.

Chief innovation officer Ian Hatton told the ABC the council would make limited use of the data.

He said personal data would not be shared with other agencies, but reports based on the data would be shared with the tourism sector.

Sydney University data privacy expert, Associate Professor Uri Gal, said Facebook would be able to see when visitors used the wi-fi service and council would potentially be able to collect a vast amount of information.

"Depending on how we define our privacy settings on Facebook, they might be able to gain information on our Facebook friends, how many friends we have, who our friends are, the likes we have on Facebook, photos we have on Facebook and so on," he said.

Professor Gal said privacy was often difficult to control for Facebook users.

"The very core of Facebook's business model revolves around the collection, analysis, distribution and reselling of user data, that is how they make their money," he said.

The move coincides with Facebook facing massive falls to its market value over concerns about the social media platform's role in data breaches.

In a statement issued after the privacy concerns were raised, the council clarified it will not access any personal data that is not publicly available.

"This access will allow council to know the age, gender and nationality of any user who logs in via Facebook," it read.

"Council will not access, store or mine for data that includes names and any other personal data of the users of the network."

'Good for the homeless'

Gold Coast residents had a mixed response to council's initiative.

Broadbeach businessman Michael Stevens said he would not use his Facebook account to access the wi-fi.

"I worked in communications in Sydney and I had concerns about what people knew about then and that was 25 years ago," he said.

"Today it is even worse, people know what you do, where you bank and what you're up to."

Broadbeach artist James Flynn said he did not think visitors would be so worried about it.

"The homeless will be happy," he said.

He said many homeless people lived around Broadbeach and would benefit from access to free wi-fi.

The free internet offer will last for the duration of the Commonwealth Games.