Google Search Reveals Credit Card Numbers 
"The search request was simple. Using a researcher's Visa debit card, we started with the first four numbers on the card and extended the span of possible number combinations. So we entered in the Google search window: visa 4060000000000000..4060999999999999." I think Google fixed this problem.
http://crm-daily.newsfactor.com/story.xhtml?story_title=Google-Search-Reveals-Credit-Card-Numbers&story_id=26967
"The search request was simple. Using a researcher's Visa debit card, we started with the first four numbers on the card and extended the span of possible number combinations. So we entered in the Google search window: visa 4060000000000000..4060999999999999." I think Google fixed this problem.
http://crm-daily.newsfactor.com/story.xhtml?story_title=Google-Search-Reveals-Credit-Card-Numbers&story_id=26967
