France's CNIL data privacy watchdog slapped 135 million euros in fines on US tech titans Google and Amazon for placing advertising cookies on users' computers without consent.

The 100-million-euro fine against Google is the largest sanction the regulator has ever imposed, which it justified by the fact 90 percent of French internet users use the firm's search engine.

CNIL said the fines were "for having placed advertising cookies on the computers of users ... without obtaining prior consent and without providing adequate information."

A cookie is a small piece of data stored on a user's computer browser that allows websites to identify users and remember their previous activity. They are important for providing targeted advertising as well as improving user experience on websites.

The CNIL said when a user visited the website, several cookies used for advertising purposes were automatically placed on his or her computer, without any action required on the user's part.

Both Amazon and Google were found by France's data privacy watchdog to have violated the privacy of internet users
Both Amazon and Google were found by France's data privacy watchdog to have violated the privacy of internet users AFP / DENIS CHARLET

It said a similar thing happened when visiting one page on the website.

The regulator said "no matter what path the users used to visit the website, they were either insufficiently informed or never informed of the fact that cookies were placed on their computer."

CNIL said the type of cookie used "can only be placed after the user has expressed his or her consent" and thus violated regulations on receiving prior consent.

It faulted Google for providing insufficient privacy information for users as it did not let them know about the cookies which had been placed and that the procedure to block them still left one operational.

CNIL said after redesigns implemented in September 2020 the websites of both firms stopped placing cookies on computers without consent.

However, it rapped both for still not providing clear or complete information about the use of the cookies and the possibility to refuse them, ordering both to make changes within three months or face additional fines.

Google complained French regulations are constantly changing
Google complained French regulations are constantly changing. AFP / Kenzo TRIBOUILLARD

CNIL imposed fines of 60 million euros on Google LLC and 40 million euros on Google Ireland Limited.

The 35-million-euro ($42-million) fine is on the Amazon Europe Core subsidiary.

When contacted, Google defended its "record of providing upfront information and clear controls" to users.

A Google representative also complained "that French rules and regulatory guidance are uncertain and constantly evolving" and overlooked its efforts to comply.

Amazon also expressed its disagreement with the fine in a statement sent to AFP.

"We continuously update our personal data protection practices to ensure we meet the needs and expectations of clients and regulators which are in constant evolution," it said in a document written in French.

The sanctions were based on French regulations before Europe's data protection regulation (GDPR) entered into force in 2018.

The GDPR stiffened fines for violations which can rise to 4 percent of a company's worldwide revenue.

CNIL has said it will begin in April 2021 to fine companies which do not meet the GDPR's requirement of having an option to accept or refuse all cookies.