the account owners should be contacted and directed to resources which will enable them to clean up and rectify the situation. Until such time as the infection is remediated the computer should be able to access only limited Internet resources.
I hope the resources they direct the account owner to, to clean up their machine, is included in that "limited internet resources". I also hope they are fully prepared to offer phone support to go along with it.
Knowing that their customers are not typically thought of as the brightest crayons in the box, AOL takes an entirely different approach. If they detect certain malware on a user's system, their software will automatically download their removal tool for it, log them out and make them run it, before allowing them to login again. And they DO offer phone support, if you are a paid subscriber.
They have been doing this for about 10 years. They don't detect all malware and it's not a substitute for antivirus software, but it does help for some situations where one may not even know they are infected. Also, in v9 of their software, it does a "security check" when you run it, before you even get the chance to login, and it will cry if it does not detect running firewall and antivirus software. (I know because I tested a special version of that software back in 2004, in a closed beta, running a firewall version that wasn't on their recognized list