What are some best practices for securely extracting and handling data from websites using PHP?

When extracting and handling data from websites using PHP, it is crucial to follow best practices to ensure data security. One key practice is to sanitize and validate input data to prevent SQL injection and cross-site scripting attacks. Additionally, use secure connections (HTTPS) when accessing external websites and avoid storing sensitive data in plain text.

// Example of sanitizing input data using PHP filter_var function
$input_data = $_GET['input_data'];
$sanitized_data = filter_var($input_data, FILTER_SANITIZE_STRING);