bp_get_activity_comment_user_id()

	function bp_get_activity_comment_user_id() {
		global $activities_template;

		$user_id = isset( $activities_template->activity->current_comment->user_id ) ? $activities_template->activity->current_comment->user_id : false;

		/**
		 * Filters the ID of the author of the activity comment currently being displayed.
		 *
		 * @since BuddyPress 1.5.0
		 *
		 * @param int|bool $user_id ID for the author of the comment currently being displayed.
		 */
		return apply_filters( 'bp_activity_comment_user_id', $user_id );
	}