Beginning Saturday, June 13, at 12:01 a.m. Eastern, social networking website Facebook will open up registration of custom usernames for its account holders. Registered trademark owners may prevent the registration of their trademarks as usernames on Facebook. If you are interested in reserving your company's trademark on Facebook, you can submit the relevant information through the site’s trademark protection contact form, which can be accessed at:  

http://www.facebook.com/help/contact.php?show_form=username_rights