Washington Post article
http://www.washingtonpost.com/wp-dyn/content/article/2008/11/24/AR2008112402125_pf.html

pointing to
http://www.webguild.org/2008/11/google-layoffs-10000-workers-affected.php

where 'Google reports to the SEC that it has 20,123 employees but in reality it has 30,000. Why the discrepancy? Google classifies 10,000 of the employees as temporary operational expenses or “workers”.'