Anthropic making a lot of noise of being the victim of large scale distillation attacks (ie other AI firms, usually Chinese copying/scraping their model), but people have pointed out the hypocrisy that Anthropic themselves seems to have copied DeepSeek.
If you bypass the system prompt and ask Claude what model it is (e.g. via Open router), it'll reply that it's DeepSeek.

(Also I know, eww Reddit and X)
Claude sonnet 4.6 says it’s DeepSeek when system prompt is empty : r/DeepSeek - https://www.reddit.com/r/DeepSeek/comments/1rd5jw7/claude_sonnet_46_says_its_deepseek_when_system/
Claude Sonnet 4.6 distilled DeepSeek? : r/DeepSeek - https://www.reddit.com/r/DeepSeek/comments/1r9se7p/claude_sonnet_46_distilled_deepseek/