What are the limitations of using temporary cookies for spam prevention in a PHP comment system, and how can developers address these limitations?

Using temporary cookies for spam prevention in a PHP comment system has limitations because cookies can be easily manipulated or deleted by users. To address this limitation, developers can implement a more secure solution such as using session variables to store information about the user's interaction with the comment system.

session_start();

// Check if the user has interacted with the comment system
if(isset($_SESSION['comment_interaction'])){
    // Process the comment
    // Add the comment to the database
    // Reset the session variable
    unset($_SESSION['comment_interaction']);
} else {
    // Display an error message or redirect the user
}