I have turned off the ability for people with a yahoo.co.uk email address to sign up for the forums. If spam accounts continue to be made with hotmail.com addresses, that'll be next on the chopping block. Followed by Yahoo.com. I'm deleting 10+ users a day and frankly, we don't care if this inconveniences you. Get a gmail account of get an account with a real domain name.
That is all.