The Canadian Civil Liberties Association is suing three levels of government over a Google-backed plan to build a smart neighbourhood in Toronto.
The association says the project is "invalid and needs to be reset".
It is run by the publicly funded Waterfront Toronto and Google-affiliated Sidewalk Labs.
Privacy advocates are concerned the project will increase surveillance and outsource government responsibilities to a private corporation.
"Canada is not Google's lab rat," said the association's executive director and general counsel MJ Bryant. "We can do better. Our freedom from unlawful public surveillance is worth fighting for."
The association is suing Waterfront Toronto, municipal, provincial and federal governments. Although Waterfront Toronto is funded through federal, provincial and municipal purses, it does not report to the city or the province.
Sidewalk Labs - a firm owned by Google's parent Alphabet - won a bid with Waterfront Toronto in October 2017 to develop a 12-acre patch of industrial landscape in Toronto, Ontario into a "smart city".
But the deal struck between the government-funded organisation and Sidewalk Labs has been mired in controversy and shrouded in secrecy.
Ontario's auditor general said oversight of the project was a concern in her report last December.
In February, the Toronto Star reported that Sidewalk Labs intends to expand onto 300 adjacent acres and build a light-rail line - in exchange for a cut of development fees and property taxes.
The land is potentially worth billions, according to the Star.
Jim Balsillie, the former co-CEO of BlackBerry, called the project a "colonizing experiment in surveillance capitalism attempting to bulldoze important urban, civic and political issues.
"Of all the misguided innovation strategies Canada has launched over the past three decades, this purported smart city is not only the dumbest but also the most dangerous".
Sidewalk Labs said it would submit its development proposal this spring to Waterfront Toronto.
In response to the lawsuit, Waterfront Toronto said it is too early to be up in arms.
"At this point Waterfront Toronto has not received a plan from Sidewalk Labs, its Innovation and Funding Partner for Quayside. Therefore, none of the claims in the in the CCLA Application can be assessed yet," Waterfront Toronto said in a written statement.