...on the list who might be able to comment on how they/you/BT is detecting downstream clients that are bot-infected, and how exactly you are dealing with them?

Unfortunately, the way you phrased that question is rather "journalistic" and in BT, as in most large companies, employees are forbidden from answering such questions without having the answers vetted by various Public Relations and Legal departments. Fortunately, published material is exempt from this rule so Googling for an article I found this: http://www.theregister.co.uk/2006/10/12/bt_spam_buster/ which contains the following: Using data from the system, BT's abuse team can cancel rogue accounts linked to spammers or add offending IP addresses to blacklists. The system also allows BT's admins to contact consumers whose compromised (zombie) PCs have unwittingly been made the part of the junk mail problem and provide advice on cleaning up their systems. Seems pretty clear to me. We take the issue of botnets very seriously and we have invested money into tools which automate some part of the process of identifying and removing bots. Just what was the point of your query? Do you have some issue with traffic emanating from BT's network? I admit that we are a rather large company with several rather widespread IP networks, nevertheless, a simple RIPE database query of "BT" does lead to more than one abuse contact and also lists several real people who you could contact directly if you need to coordinate activity. --Michael Dillon