This is a really insensitive reply. I say this as a reader who did not have a "shitfit" when I heard about this and found metadata about me on last.fm. While it is not something that I personally am overly worried about, I can understand that there are many legitimate reasons why someone would be concerned over this. One such reason (and the reason why I've been signal boosting the issue) is that there are a lot of people who don't actually think about the many risks that being on the internet can present. I think about my online presence all the time, regardless of whether that presence is in a "private" environment or not, because I don't actually trust any site to maintain my privacy. That's my own personal choice, though, and there are many people who don't think about their internet privacy (or lack thereof) because they've grown up in (or gotten used to) an environment where internet interaction is extremely casual. In addition, despite the changing environment, many people still think of fandom as an "underground" thing and they're not used to having fannish things spotlighted in mainstream media. And, as pandarus said above, there's a difference between putting yourself out there in fannish spaces versus mainstream spaces.

Just because this isn't something you would be freaked out over (and this doesn't actually affect you personally anyway) doesn't mean you should dismiss other people's concerns.