What are the potential legal issues when integrating external content into a PHP web application?

One potential legal issue when integrating external content into a PHP web application is copyright infringement. To avoid this issue, it is important to ensure that you have the necessary permissions to use the external content or that the content is properly licensed for use.

// Example of checking for permissions before using external content
$externalContent = file_get_contents('http://example.com/external-content');
if ($externalContent) {
    // Check permissions or licensing terms before using the content
    echo $externalContent;
} else {
    echo 'Error retrieving external content';
}