Nothing bad has happened to me because of this, and one may argue that targeted ads are better than non-targeted. But I do not like the idea of being tracked – and I shut off all web ads anyway with AdBlock. Additionally, I have NoScript always on (and allow sites selectively each time when “some site does not work”).
I have quite long “accept-language” header set in my browsers, as I can read web pages in several languages. panopticlick shows that I’m one such user out of about half million (it might be that I’m just the only one with this value of accept-language, who made a check there).
I’m not feeling paranoid because of this. But I’ll be happy to know, is there a way to pass my (complicated 🙂 ) language preferences without allowing for easy fingerprinting.