The article mentions the FBI investigation but is not about that. This article is about a pressure campaign, the letter Web Abuse Association Defense sent to adguard making threats under french law and adguard's investigation in response to that letter.

A French organization with an English name, writing in English? J'en doute.

Very many European citizens speak English and it's the lingua franca* of the Internet.

It was exceptionally clear from reading their writing, they are NOT native English speakers.

It seems 57% of people in France can speak English, which I can easily believe:

https://en.wikipedia.org/wiki/List_of_countries_by_English-s...

No reason to doubt this is coming from a French person.

Which was what my parent comment referred to. Comments replying to mine act like it's unreasonable for me to talk about US federal agents in the context of this subject, when those are what the article mentions specifically, many times.