While software systems tend to strive towards accuracy and fidelity, I have frequently observed that these exact qualities may hurt social software.
When you walk down the hall and see someone you know, you raise your eyebrows to acknowledge their existence, and expect the same from them. If they don't reciprocate, you can plausibly tell yourself that perhaps they didn't see you, or were otherwise distracted. However, when you send someone an instant message, and they never reply, you can be reasonably sure they got it and are ignoring you. Thankfully, in the email world, we can at least blame the spam filter as to why you never replied.
It occurs to me that not every factoid gleaned from the constellation of behavioral data should be presented.
For example, the emminently social Twitter, happily informs me that while 34 people count themselves amongst my friends, only 31 of them care to be informed about I'm up to every day -- and then shows me who those folks are. While these lists are on different actual web pages, it's not a herculean task to figure out the actual people involved. Even though it's possible to show all the information, from a social perspective a degraded view would be better.