How to add reCaptcha to Pardot Form Handlers

We are using Pardot Form Handlers for a few special use cases such as

Quick notes

<span class="validate-email-msg" id="cases-error-captcha"></span>
<div class="g-recaptcha" id="recaptcha" data-sitekey="site-key-here-138499138"></div>
  if ( $('#support-contact-cases') ) {
$('#support-contact-cases').submit(function(e){
// this.submit();

var $captcha = $( '#recaptcha' );
var response = grecaptcha.getResponse();

$contactName = $('#firstname').val() + ' ' + $('#lastname').val();
$contactComments = $('#case-description');
$('#contactname').val($contactName);
var output = $contactComments.val() + '\n\n' + date;

$contactComments.val(output);

if (response.length === 0) {
e.preventDefault();
$( '#cases-error-captcha').text( "reCAPTCHA is required" );
console.log('error');
if( !$captcha.hasClass( "error" ) ){
$captcha.addClass( "error" );
}
} else {
$( '#cases-error-captcha' ).text('');
console.log('good');
$captcha.removeClass( "error" );
return true;
}
});
}

Let me know what you think on twitter @rdallaire