To those who are afraid of reading articles it's about people giving Claude passwords and they end up in a repo. Here is a copy paste from part of it

The file is meant to stay on the developer’s machine, and Claude Code tries to keep it there. When it creates the file inside a git repo, it adds it to the developer's global git ignore list. That covers the common case. It doesn’t cover a folder that becomes a repo later, a clone on another machine, or a file someone already committed. The rule never goes into the repo's own .gitignore, so nothing travels with the project to protect it

I'm sorry. We use ai all the time at work but you can't just vibe Code your projects. You have to be involved.