bp_get_activity_user_id()

	function bp_get_activity_user_id() {
		global $activities_template;

		/**
		 * Filters the activity user ID.
		 *
		 * @since BuddyPress 1.1.0
		 *
		 * @param int $user_id The activity user ID.
		 */
		return apply_filters( 'bp_get_activity_user_id', $activities_template->activity->user_id );
	}