It’s an official campaign run by the EDRi (European Digital Rights), so I would deem it to be legit. If you trust the EDRi’s members, I wouldn’t worry toooo much.

I found out about the petition from the German organizations “Digitalcourage” and the “CCC” - and at least personally, I do trust them.

Edit: I changed the post description a little bit, due to the concerns you raised. Thanks! I hope this makes it a bit clearer for people.