how did you work that out?
To put it simply, I traced their IP address, and came up with a post code, BT6.
if they've been bothered enough (and sad enough) to sign up to a different Yahoo address or something...
Yes, but the choice of email address can tell you alot, and if they have filled out a member profile...
Plus if they have a dynamic IP.
Yes, that is possible, they are on DSL, possibly Wanadoo, which does give Dynamic IP's, but always within a certain range based on which station you connect to.