> Once in my practice I've met an ISP who blocked their client,
> and when he contacted call-center he was told "Your account was
> suspended, because your computer is heavily infected. Please clean it
> up, send us a list of viruses you've identified there, and we will renew
> your account".
Comcast (big US cable ISP) does something like this. I experienced it
firsthand when a house-guest had an infected laptop. Comcast applied
filtering to outbound port 25. They then sent me an email explaining
that they had detected spam from my location, suggested ways to check
all my PCs for malware (Comcast also provides a free Norton security
suite to all customers), and told me how I could get port 25 unblocked.
I thought that was remarkably cool: proactive and fair.
(All my machines were clean, and it was only the house-guest who had a
problem. I didn't bother getting port 25 unblocked since I was able to
easily switch all of our MUAs to port 587.)
