public function findFriends($numbers, $country = 'US') {
		$batches = array_chunk(array_flip($numbers), 30, TRUE);

		// Make sure we're logged in and have a valid access token.
		if (!$this->auth_token || !$this->username) {
			return FALSE;
		}

		$results = array();
		foreach ($batches as $batch) {
			$timestamp = parent::timestamp();
			$result = parent::post(
				'/find_friends',
				array(
					'countryCode' => $country,
					'numbers' => json_encode($batch),
					'timestamp' => $timestamp,
					'username' => $this->username,
				),
				array(
					$this->auth_token,
					$timestamp,
				)
			);

			if (isset($result->results)) {
				$results = $results + $result->results;
			}
		}

		return $results;
	}