Not to be argumentative, but by that logic, I guess it is okay to drive my 1948 Ford which doesn't have brakes if I don't have the cash to fix it.
This is a matter of opinion. While this was my initial first thought, I can't agree with it. An old PC is by no means a threat to others. The invasive and unlawful actions of a third party is what turns the computer into a threat. I'd rather compare this with Canadian winter. It is so cold out that I have to start my vehicle and let it idle for a few minutes. This means an unattended vehicle with the key in the ignation. If the neighbours kid takes the vehicle and plays impersonates "Grand Theft Auto", who's responsible for the damage? As owner, at which point have I taken reasonable precautions against such an event? There are programs happening which refurbish and distribute retired corporate PC's to schools and other organizations. All of this equipment is as I described. There are an enormous number of PC's out there that match the situation I described... But that's all really not all that important to my question. What I really need is an easy to use solution to deal with the problem. Emphasis is on "easy to use" not necesarily easy to implement.