Oh yeah, all that (and more) is possible...but like you said, that's all pretty surface stuff, and I try to be careful about what people see about me online.

That said, I'm happy to discuss music with pretty much anyone, pretty much any time, so my LastFM and Pandora stats & feeds are wide open; my Twitter feed is public, so I'm comfortable with that appearing here; and I restrict my Flickr feed to public photos, so photos of my family (for example) do not appear here (or to the public on my Flickr page). My usage info from Foursquare is not public, neither is anything personal I have on Facebook, so none of that stuff appears here.

When it comes to my own user profile (for lack of a better term) on the internet, I always strive for a balance of transparency and privacy: I use a layering strategy (public / personal / private / offline) to determine the sanctity of personal info and who has access to it, and ultimately, I always follow one simple rule: If I'm not comfortable with it out in the world, I don't put it on the internet.

Oddly enough, I've been thinking a lot about what social tools I use online and why, and I'm working on a blog post about that...so stay tuned if you're so inclined.

Good question, by the way. Thanks!

(BTW... The question got chopped into two; the first part of it read: "that part about stalking is a little crazy- what you listen to, etc.- i didn't realize that was possible- to have that level of access to a persons life. Understandably it's just surface stuff, but it's weird to think someone out there you've never met...")