You can easily add “flogs-hidden” (without the quotes) to your Lodestone profile to opt out without having to create an account on the website. However, you may end up blacklisted by PF groups and statics for doing so.

Personally, I don’t mind being parsed by someone else and having my data uploaded. You don’t need a parser to tell when someone isn’t playing well or contributing to DPS. I still don’t quite understand why people hide things like their achievements on Lodestone or their parses. Anyway, anyone that uses parsing or fflogs to harass other players is doing it wrong.