client/lib/analytics/ad-tracking.js
function initFacebook() {
	if ( user.get() ) {
		initFacebookAdvancedMatching();
	} else {
		window.fbq( 'init', TRACKING_IDS.facebookInit );

		/*
		 * Also initialize the FB pixel for Jetpack.
		 * However, disable auto-config for this secondary pixel ID.
		 * See: <https://developers.facebook.com/docs/facebook-pixel/api-reference#automatic-configuration>
		 */
		window.fbq( 'set', 'autoConfig', false, TRACKING_IDS.facebookJetpackInit );
		window.fbq( 'init', TRACKING_IDS.facebookJetpackInit );
	}
}
function initFacebook() {
	if ( user.get() ) {
		initFacebookAdvancedMatching();
	} else {
		window.fbq( 'init', TRACKING_IDS.facebookInit );

		/*
		 * Also initialize the FB pixel for Jetpack.
		 * However, disable auto-config for this secondary pixel ID.
		 * See: <https://developers.facebook.com/docs/facebook-pixel/api-reference#automatic-configuration>
		 */
		window.fbq( 'set', 'autoConfig', false, TRACKING_IDS.facebookJetpackInit );
		window.fbq( 'init', TRACKING_IDS.facebookJetpackInit );
	}
}
Initializes the Facebook pixel.

When the user is logged in, additional hashed data is being forwarded.