http://stallman.org/stallman-computing.html
> "If I am visiting somewhere and the machines available nearby happen to
contain non-free software, through no doing of mine, I don't refuse to touch
them. I will use them briefly for tasks such as browsing. This limited usage
doesn't give my assent to the software's license, or make me responsible its
being present in the computer, or make me the possessor of a copy of it, so I
don't see an ethical obligation to refrain from this."
In my opinion using those is accepting those are being used (in school) and
hence supporting non-free software. I am quite surprised to see how liberal
Stallman is in that.