Search by email address in members?

I would like to suggest an enhancement to search Members by email address. At present you can only search by Member name (as far as I can tell). For example I NEVER get members with an address - never! And lately I've had a few spam users slip through. I'd love to be able to search for outlook or yahoo or hotmail and then deactivate all of those accounts. Even though I believe my membership is locked down pretty well, I would love to keep those accounts out. I notice that in "users" I also can only search by user name, and so I assume that Members is built on the same basic code. eNewsletter will search in the email field though, and I think it would be nice to have that in Membership.