France’s data privacy watchdog has handed out its biggest ever fine of 100 million euros ($121 million) to Alphabet’s Google for breaching the country’s rules on online advertising trackers (cookies).

The CNIL said on Thursday it had also fined e-commerce giant Amazon 35 million euros for breaking the same rules.

The regulator found the companies’ French websites didn’t seek the prior consent of visitors before advertising cookies — small pieces of data stored while navigating on the Web — were saved on computers, it said in a statement.

Google and Amazon also failed to provide clear information to Internet users about how the firms intended to make use of such online trackers and how visitors to their French websites could refuse any use of the cookies, the watchdog said.

The CNIL rejected the companies' arguments that it had no right to impose the sanctions because their respective European headquarters are in Ireland and Luxembourg — two countries perceived by some data privacy advocacy groups as being lenient towards Silicon Valley companies.

Google’s fine had to be paid for the most part by its US entity Google LLC (60 million euros) and the rest by EU-based Google Ireland Limited (40 million). Amazon’s fine has to be paid by its Luxembourg-based entity.