You may have read thatit was a big week for Bluesky.If youre not familiar, Bluesky is, essentially, a Twitter clone that publishes short-form status updates. It gained more than 2 million users this week. On Wednesday,The Vergereportedit had crossed 15 million users. By Thursday, it was at 16 million. By Friday?17 million and counting. It was thenumber one appin Apples app store.Meanwhile, Threads, Metas answer to Twitter, put up even bigger numbers. The companys Adam Mosserireported that 15 million peoplehad signed up in November alone. Both apps are surging in usage.Many of these new users were seemingly fleeing X, the platform formerly known as Twitter. On the day after the election, more than115,000 people deactivated their X accounts, according to Similarweb data. Thats a step far past not logging on. It means giving up your username and social graph. Its nuking your account versus just ignoring it.Much of that migration is likely a reaction to Elon Musks support of Donald Trump, and his moves to elevate right-leaning content on the platform. Since Musk took over, X has reinstated a lot of previously banned accounts, very many of which are on the far right. It also tweaked its algorithm to make sure Musks own posts, which are often pro-Trump, get an extra level of promotion and prominence,according toKate Conger and Ryan Macs new bookCharacter Limit.There are two points I want to make here. The first is that tech and politics are just entirely enmeshed at this point. Thats due to the extreme extent to which tech has captured culture and the economy. Everything is a tech story now, including and especially politics.The second point is about what I see as a more long-term shift away from centralization. Whats more interesting to me than people fleeing a service because they dont like its politics is the emergence of unique experiences and cultures across all three of these services, as well as other, smaller competitors.Last year,we put Twitter killers on our list of 10 breakthrough technologies. But the breakthrough technology wasnt the rise of one service or the decline of another. It was decentralization. At the time, I wrote:Decentralized, or federated, social media allows for communication across independently hosted servers or platforms, using networking protocols such as ActivityPub, AT Protocol, or Nostr. It offers more granular moderation, more security against the whims of a corporate master or government censor, and the opportunity to control your social graph. Its even possible to move from one server to another and follow the same people.In the long run, massive, centralized social networks will prove to be an aberration. We are going to use different networks for different things.For example, Bluesky is great for breaking news because it does not deprioritize links and defaults to a social graph that shows updates from the people you follow in chronological order. (It also has a Discover feed and you can set up others for algorithmic discoverymore on that in a momentbut the default is the classic Twitter-esque timeline.)Threads, which has a more algorithmically defined experience, is great for surfacing interesting conversations from the past few days. I routinely find interesting comments and posts from two or three days before I logged on. At the same time, this makes it pretty lousy at any kind of real time experienceseemingly intentionallyand essentially hides that standard timeline of updates from people you follow in favor of an algorithmically-generated for you feed.Im going to go out on a limb here and say that while these are quite different, neither is inherently better. They offer distinct takes on product direction. And that ability to offer different experiences is a good thing.I think this is one area where Bluesky has a real advantage. Bluesky lets people bend the experience to their own will. You arent locked into the default following and discover experiences. You canroll your own custom feed, and follow custom feeds created by other people. (And Threads isnow testing something similar.) That customization means my experience on Bluesky may look nothing like yours.This is possible because Bluesky is a service running on top of the AT Protocol, an open protocol thats accessible to anyone and everyone. The entire idea is that social networking is too important for any one company or person to control it. So it is set up to allow anyone to run their own network using that protocol. And thats going to lead to a wide range of outcomes.Take moderation, as an example. The moderation philosophy of the AT Protocol is essentially that everyone is entitled to speech but not to reach. That means it isnt banning content at the protocol level, but that individual services can set up their own rules.Bluesky hasits own community guidelines. But those guidelines would not necessarily apply to other services running on the protocol. Furthermore, individuals can also moderate what types of posts they want to see. It lets peopleset up and choose different levels of what they want to allow. That, combined with the ability to roll your own feeds, combined with the ability of different services to run on top of the same protocol, sets up a very fragmented future.And thats just Bluesky. Theres also Nostr, which leans toward the crypto and tech crowds, at least for now. And Mastodon, which tends to have clusters of communities on various servers. All of them are growing.The era of the centralized, canonical feed is coming to an end. Whats coming next is going to be more dispersed, more fractured, more specialized. It will take place across these decentralized services, and also WhatsApp channels, Discord servers, and other smaller slices of Big Social. Thats going to be challenging. It will cause entirely new problems. But its also an incredible opportunity for individuals to take more control of their own experiences.If someone forwarded you this edition of The Debrief, you cansubscribe here. I appreciate your feedback on this newsletter. Drop me a line atmat.honan@technologyreview.comwith any and all thoughts. And of course, I love tips.Now read the rest of The DebriefThe NewsTSMC halts advanced chip shipments for Chinese clients. It comes after some of its chips were found inside a Huawei AI processor.Google DeepMind has come up with a new way to peer inside AIs thought process.An AI lab out of Chicago is building tools to help creators prevent their work from being used in training data.Lina Khan may be on the way out, but shes going out with a bang: The FTC is preparing to investigate Microsofts cloud business.The ChatEvery week Ill talk to one of MIT Technology Reviews reporters or editors to find out more about what theyve been working on. For today, I spoke with Casey Crownhart, senior climate reporter, about her coverage of the COP29 UN climate conference.Mat: COP29 is happening right now in Azerbaijan, do you have a sense of the mood?Casey: The vibes are weird in Baku this week, in part because of the US election. The US has been a strong leader in international climate talks in recent years, and an incoming Trump administration will certainly mean a big change.And the main goal of these talksreaching a climate finance agreementis a little daunting. Developing countries need something like $1 trillion dollars annually to cope with climate change. Thats a huge jump from the current target, so there are questions about how this agreement will shake out.Mat: Azerbaijan seems like a weird choice to host. I read one account from the conference saying you could smell the oil in the air. Why there?Casey: Azerbaijans economy is super reliant on fossil fuels, which definitely makes it an ironic spot for international climate negotiations.Theres a whole complicated process of picking the COP host each yearfive regions rotate hosting, and the countries in that region have to all agree on a pick when its their turn. Russia apparently vetoed most of the other choices in the Eastern European group this year, and the region settled on Azerbaijan as one of the only viable options.Mat: You write that if Trump pulls out of the UN Framework Convention on Climate Change, it would be like riding away on a rocket. Why would that be so much worse than dropping out of Paris?Casey: Trump withdrew from the Paris Agreement once already, and it was relatively easy for Biden to rejoin when he came into office. If, during his second term, Trump were to go a step further and pull out of the UNFCCC, its not just an agreement hes walking away from, its the whole negotiating framework. So the statement would be much bigger.Theres also the question of reversibility. Its not clear if Trump can actually withdraw from the UNFCCC on his own, and its also not clear what it would take to rejoin it. When the US joined in the 90s, the Senate had to agree, so getting back in might not be as simple as a future president signing something.Mat: What from COP29 are you optimistic about?Casey: Tough to find a glimmer of hope in all this, but if there is one, Id say Im optimistic that well see some countries step up, including the UK and China. The UK announced a new emissions target at the talks already, and itll be really interesting to see what role China plays at COP29 and moving forward.The RecommendationOnce upon a time I was a gadget blogger. Its fun writing about gadgets! I miss it! Especially because at some point your phone became the only device you need. But! My beloved wife bought me a Whoop fitness tracker for my birthday. Its an always-on device that you wear around your wrist. Ive been Oura-curious for some time, but frankly I am a little bit terrified of rings. I spent a number of months going to a hand rehab clinic after a bike accident, and while I was there first learned about degloving and how commonly it happens to people because a ring gets caught on something. Just thought Id put that in your head too. Anyway! The whoop is a fabric bracelet with a little monitor on it. It tracks your movement, your heart rate, your sleep, and a lot more. Theres no screen, so its very low profile and unobtrusive. It is, however, pretty spendy: The device is free but the plan costs $239 annually.