The security doesn't, but availability might: the relay is very easy to DoS (not even DDoS!). This is the one thing that I think Thomas has jumped the gun on with his recommendation: the current protocol and infrastructure won't survive a DoS attack, which is tragically likely if magic-wormhole's popularity increases. Brian Warner is aware of this and has written about it.

https://github.com/warner/magic-wormhole/blob/master/docs/at...

https://github.com/warner/magic-wormhole/issues/107

https://github.com/warner/magic-wormhole/issues/150

I noticed the same issue as Joey Hess, except a couple of years later; then when I was giving a magic-wormhole demo, some of the audience members accidentally broke some of my live transfers in various ways.

(Otherwise, I feel just as gleeful as Thomas does. It's an awesome tool and fun to use!)