You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract In Virtual Strike, Belgium's Ad Agencies Close Their Sites Marketers Ignore Pitch Rules, Leading Shops to Protest and Host Open Letter By Laurel Wentz, Published on February 10, 2010 17 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Become a Member Already a member? Log in.