Unless the GPL was enshrined in some law I'm not aware of, it's likely to be a a breach of contract, not necessarily "illegal". If a court rules against you, in most cases the worst that can happen is having to pay some redress to the developer and stopping what you were doing.
Unless the GPL was enshrined in some law I'm not aware of, it's likely to be a a breach of contract, not necessarily "illegal". If a court rules against you, in most cases the worst that can happen is having to pay some redress to the developer and stopping what you were doing.