Actually, something a little curious here. And perhaps sinister. read on...
 As I guess you know, I use a gmail account for my mail.
 And as you may also know, Google gets (some of) their revenue by
 putting 'targeted' ads on the sidebars of their gmail web page.
 And you may also have heard some mutterings about the security of
 people letting Google see their mail.
Today I got a mail from a colleague. He had sent it to himself, Bcc:ed
to a list of recipients. Obviously, none of the recipients can see who
else is getting the mail. But I suspect Google leaked a clue into its
sidebar ads.
 Quotes from Google Mail Help page:
 Sidebar links
 Google Mail uses a completely automated process to provide useful
 information and relevant ads in the sidebar of your Google Mail
 account pages:
 Ads and Related Pages
 Ads in Google Mail are placed in the same way that ads are placed
 alongside Google search results and, through the Google AdSense
 programme, on content pages across the web. The goal is to provide
 users with helpful ads, links and content relevant to their specific
 interests. Google Mail is a technology-based programme. Advertising
 and related information are shown using a completely automated
 process.
 ...  Google Mail displays text ads using our contextual advertising
 technology. These ads should be relevant to the content of your
 messages and we hope you'll find them useful.
 <end quotes>
Now this message said simply:
From: "Percy.A.ColleagueOfVictors." <xxx@???>
To: <xxx@???>
Subject: Percy Away on business in Spain 7-9 April
Date: Fri, 4 Apr 2008 12:43:03 +0100
 So I am a bit curious as to how it contextually came up with the
 following set of ads. I can understand it picking up on Spain, but the
 list of names....?
 [begin copy]
 PRINCE 2 Courses
 London/Bournemouth From £895 Foundation/Practitioner Courses!
 
www.Cupe.co.uk
 Cycling Holidays in Spain
 5 to 12 day Tours April to October A great way to see Spain
 
www.iberocycle.com
 3 Star Hotel in Jerez.
 Enjoy our new April holiday Offers Book 5 nights, pay only 4 nights.
 
www.hotelchancilleria.com/
 More about
 Percy »
 Tom Waits »
 Tom Welling »
 Tom Wood »
 Tom Townsend »
 Tom Tryon »
 Tom Tucker »
 Tom Turner »
 [end copy]
 I hypothesise that one of the people in my colleague Percy's Bcc:
list is called Tom
 and that Google has 'leaked' that information into its ad-selecting .
 Am I right? And should I report this to the Google guys?