Can I get a free GPU?

I'm curious, can you actually obtain a free GPU for use in cryptocurrency mining or other purposes? It seems like a pretty valuable piece of hardware, so I'm wondering if there are any legitimate ways to acquire one without having to pay for it. Is there a specific program or giveaway that you're aware of that offers free GPUs? Or is it more likely that one would have to invest their own money to get their hands on one?