Steve Fosdick fozzy@pelvoux.demon.co.uk writes:

I take there has been a report on this kind of activity. DOes anyone have any details please?

I can't remember which one, but I think it was Yahoo!. Basically, their advertising sales team was going out and trying to sell ad space on their web mail with the demographics and behavioural data on their users. Of course, this all came from the adverts, not from the actual emails, but the user tracking in there was active and it did tell them more than you really want known about you.

It seems to me that it's only a small step to doing analysis on the actual emails to see how to market more effectively at you, and in some legislations that would be perfectly legal.