That's the official position. I'm pretty sure, but of course I'm not suggesting you do so, that if you pay with a prepaid credit card and call yourself Random Person you will have no problem. As I said in another thread you can also just show up and buy ticket cash at the entrance from whomever sells them, but of course you risk not getting a ticket. Depends on your concerns. I'm pretty sure if you have a better solution but such large scale event you can contribute directly.

I'm also pretty sure if you have something genuinely uniquely valuable to contribute but can only participate anonymously you can contact organizers and they'll find a way, regardless of ticket availability.