This can require quite the sales job.
DOES create a risk, even if they are using a non-DID phone line.
It is also assumed that the PC may have the full set of Internet services installed, which we've found is the default for many OSs, and which, if it is not the default, can easily be loaded by most people determined they want to use the services. This information will be used in awareness messages and discussions with employees about why, typically, they need to access the Internet through the firewall. I've had some requests to post the responses I received. The following is a summary of the responses, along with some additional information I found after I posted the question. Since several of the responses were similar, I'm omitting attributions to them.