I am wondering whether the following implication is true:
If a driver from linuxwireless.org is not available in Trisquel then it includes non-free software.
I once got a chipset work with a driver downloaded from there just to find out later that this particular driver was non-free, so I finally sent the hardware back. Anyway, as aliasbody mentioned, I think it harms less to install one non-free driver compared to installing a non-free OS, and very often, the wireless card is the only critical component.
