What are the implications of allowing web crawlers like Google to access PHP files with sensitive information?

Allowing web crawlers like Google to access PHP files with sensitive information can lead to a security risk as these files may contain database credentials, API keys, or other confidential data. To prevent this, you can use the `robots.txt` file to block search engines from crawling specific directories or files that should not be publicly accessible.

User-agent: *
Disallow: /path/to/sensitive/files/