function bp_activity_mark_as_ham( &$activity, $source = 'by_a_person' ) {
	$bp = buddypress();

	$activity->is_spam = 0;

	// Clear the activity stream first page cache.
	wp_cache_delete( 'bp_activity_sitewide_front', 'bp' );

	// Clear the activity comment cache for this activity item.
	wp_cache_delete( $activity->id, 'bp_activity_comments' );

	// If Akismet is active, and this was a manual spam/ham request, stop Akismet checking the activity.
	if ( 'by_a_person' == $source && !empty( $bp->activity->akismet ) ) {
		remove_action( 'bp_activity_before_save', array( $bp->activity->akismet, 'check_activity' ), 4 );

		// Build data package for Akismet.
		$activity_data = BP_Akismet::build_akismet_data_package( $activity );

		// Tell Akismet this is spam.
		$activity_data = $bp->activity->akismet->send_akismet_request( $activity_data, 'submit', 'ham' );

		// Update meta.
		add_action( 'bp_activity_after_save', array( $bp->activity->akismet, 'update_activity_ham_meta' ), 1, 1 );
	}

	/**
	 * Fires at the end of the process to mark an activity item as ham.
	 *
	 * @since 1.6.0
	 *
	 * @param BP_Activity_Activity $activity Activity item being marked as ham.
	 * @param string               $source   Source of determination of ham status. For example
	 *                                       "by_a_person" or "by_akismet".
	 */
	do_action( 'bp_activity_mark_as_ham', $activity, $source );
}