Until yesterday evening, one of the best ways of discovering new people on Twitter was to observe whom your friends talked to. For those of you who aren't familiar with Twitter, these messages typically look something like this:

In this hypothetical example, I'm sending a tweet to my fellow All Tech blogger Eyder Peralta. Anyone who subscribed to my tweets would see this message, and some of them might click through to Eyder's tweets to see the rest of the conversation. It's your choice, of course, but when you see a reply that references someone else and it's an interesting discussion, you might end up making a new contact out of it. I'd guess I've discovered more than half the people I'm following on Twitter this way.

Unfortunately, that's no longer possible. With Twitter's update last night, you won't see any more tweets from your friends that are replies to people you don't know. So if you were following me on Twitter but not Eyder, to continue with the above example, that tweet would not even exist as far as you're concerned. You'd never see it, and you'd never get the opportunity to meet Eyder in the process.

Here's how Twitter's Biz Stone explained the change on their blog:

We've updated the Notices section of Settings to better reflect how folks are using Twitter regarding replies. Based on usage patterns and feedback, we've learned most people want to see when someone they follow replies to another person they follow--it's a good way to stay in the loop. However, receiving one-sided fragments via replies sent to folks you don't follow in your timeline is undesirable. Today's update removes this undesirable and confusing option.