The problem with making changes to a large and popular social networking site, is that you're bound to annoy someone. Facebook learnt that one the hard way, and now Twitter's facing a user backlash over changes that it's made to how @replies work.
Originally, users were able to select from three options - view no @replies, view @replies to and from people you follow, and view @replies from people you follow to anyone else. It let people choose how much stuff they wanted in their feed.
Many people went for the first and second options, as the third option often subjects you to having to hear just one side of a conversation. However, Twitter has now removed that choice.
Users are upset, with a #fixreplies hashtag firmly at the top of the trending topics at the time of writing. It turns out that people quite liked discovering new users by seeing who their friends were messaging.
It'll be interesting to see how Twitter reacts, and what they do about the problem. Most analysts expect a fairly swift roll-back of the old system, followed by Twitter opening a dialogue with its users about how to approach @replies in the future.