Speaker 1: At a new development around Chinese AI startup DeepSeek, it says it's now temporarily restricting who can log into its chatbot app, allowing only China-based mobile phone numbers because of large-scale malicious attacks. American users can still use their email to sign in. Dierdre Bosa digs into the implications of its rise among U.S. consumers for today's Tech Check, and Di, you were early, maybe first on this whole thing.

Speaker 2: We knew it was big maybe a month ago, but we never imagined it would be this biggest story, even moving the markets this morning. But this latest development, a potential cyber attack, it really adds to the intrigue surrounding this Chinese AI lab that has really upended everything we thought we knew about the race in AI and raising the stakes because it's already been unleashed here. American users have flocked to the DeepSeek app en masse. Over the weekend, I watched in disbelief as it climbed the App Store charts, landing at number one sometime yesterday overtaking, guess who, ChatGPT. Today, it's blowing up on Google Trends. Now, consumer adoption marks a fundamental shift in the AI race. Until now, much of the momentum has been developer-driven because this is an open-source model. So that means that developers can use and tweak the model to suit their own needs, whether that's removing censorship or building entirely new applications on top of it or using its infrastructure. Still, that's something that Perplexity CEO, Arvind Sridivas, told me could be concerning.

Speaker 3: What's more dangerous is they have the best open-source model and all the American developers are building on that. That's more dangerous because then they get to own the mindshare, the ecosystem, the entire American AI ecosystem. Look, in general, it's known that once open-source is caught up or improved over closed-source software, all developers migrate to that.

Speaker 2: Open-source can also make it more vulnerable, potentially leading to what we are seeing this morning. And when it comes to a polished consumer-facing app like DeepSeek on the App Store, this risk is amplified. Consumers receive the product as it was designed, and in this case, parameters set or censored by the Communist Party of China. Its rapid climb to number one on the App Store suggests that millions of consumers outside of China are embracing an open-source tool whose outputs are, at least to some degree, filtered and influenced by Chinese government priorities. Put another way, this makes TikTok look like a warm-up act.