Remind me of a joke:

Why is six afraid of seven?

And in france it was many times in the news about a group of friends who were arrested for using Signal.

Citation needed. Your third- or fourth-hand account is so vague that I wonder if the devil has been lost along with the details.

It piqued my curiosity. The only references I could find were the Telegram CEO being arrested earlier this year (widely reported on) and a group arrested in 2023 for associating with a Kurdish militant faction (YPG). That incident had some misdirected media attention towards the encryption tools used.