Looks interesting, it's certainly something that, well executed, could add a lot of value.

Do you have a mockup of how it would look like?

I'm currently thinking of a meld of stuff like Delicious or Stumble Upon or Longreads. Being more passive than Delicious or Stumble Upon should be a win, but would also increase the noise ratio.

I don't understand the " what people in your network are interested in rather than what they want to appear when they choose to share selectively" - for example, if I'm researching technical stuff, I'm not sharing because I KNOW that people in my network don't want to know the latest about obsolete 4GL languages. Or embarrassing StackOverflow queries :) . Would those be shared?