Furniture retailer Ikea has been fined €1 million ($1.2m) for spying on hundreds of workers and unhappy customers as part of a campaign to collect data on union representatives.
Two former executives convicted for their part in the spying scandal were fined and given suspended prison sentences.
Ikea's French subsidiary set up an elaborate system to spy on hundreds of employees and job applicants between 2009 and 2012, and to profile unhappy customers, using private detectives and police sources, the court was told.
In disputes with customers, the company would trawl for data on people's finances and the cars they drove, the court heard.
"In France, it's rare that big companies are convicted like this and therefore I am happy," said whistleblower Adel Amara, a former Ikea employee.
"It's true that €1m for Ikea is nothing at all. But it is symbolic and we must be happy with our judicial system in France because the justice system is here for the citizens and it has shown today that is has reacted.
"It's true that €1m is not a lot but people have been convicted and it's a start."
The French subsidiary of Ingka Holding, which owns Ikea stores worldwide, was accused of snooping on its workers and customers.
Jean-Francois Paris, the executive in charge of risk management at the time of the spying, said that up to €630,000 a year was set aside for such investigations.
About 400 employees became targets of the programme, state prosecutor Pamela Tabardel told the court.
"What's at stake is the protection of our private lives against the threat of mass surveillance," she said during the trial.
Paris was convicted of fraudulently gathering personal data, fined €10,000 and received an 18-month suspended sentence.
Former Ikea France chief executive Jean-Louis Baillot was convicted of receiving fraudulently collected data and complicity in the scheme. He was fined €50,000 and given a two-year suspended sentence.
"This has set up a red light, if I may say. It doesn't prevent you from going through a red light, but this is nevertheless a clear warning," said Solenne Debarre, a lawyer for the plaintiffs.
The flat-pack furniture group, which has recognised there were some improper practices, was accused of breaching employees' privacy by looking at records of their bank accounts and sometimes using fake employees to write up reports on staff.
Baillot, who was in charge from 1996 to 2002, denied any wrongdoing during the trial that began in March in the Paris suburb of Versailles.
He said he was "shocked" by the ruling and is weighing an appeal, said his lawyer, Francois Saint-Pierre.
The trial focused on spying allegations that dated from 2009 to 2012, but prosecutors say the system was set up nearly a decade earlier under Baillot's watch.