[bornfreddy]

The big gotcha is what one understands under the word "use". If I want to USE it as a basis for my business where I sell routers with the GPL software, there are some tiny restrictions regarding that, as Linksys learned [0].

[0] https://en.wikipedia.org/wiki/OpenWrt (see History section)

[rbanffy]

That’s correct. You can’t take freedoms away from your downstream users. As I said before, violating a free software license usually means you are stealing from your users, negating them rights they ought to be given.