Why Does It Feel Like DeepSeek Came Out of Nowhwere?

The video discusses a new company and its model, which emerged rapidly and inexpensively, raising questions about US-China tech restrictions. The model's techniques are familiar in the industry, but its speed and cost efficiency are notable. Deep Seek, the company in question, has restricted new sign-ups to users with Chinese phone numbers, possibly due to a surge in demand and potential malicious activity.

What might be the reasons for Deep Seek restricting new sign-ups to users with a Chinese telephone number?

How could the surge in sign-ups affect Deep Seek's ability to manage its user base?