They could accomplish the same thing using 2-D barcodes / image-recognition software - accessed by a players cell phone camera and then posted online. This way players could update and track their scores on non-internet enabled arcade games.
Ideally - and Buck Hunter doesn't feature this - your cell phone could unlock bonus stages. Furthermore, in any scenario where the arcade is internet-enabled your friends could assist you to unlock stages and bonus stages. Rather than a lengthy log-in / authentication sequence via the arcade's interface, a player's phone is the simplest way to access your social graph. Just like friends can cheer you on from Facebook using Nike+, friends on Facebook could impact your gameplay as you churn through the Serengeti capping off endangered animals - something I once enjoyed quite a bit.
I'm not sure when Arcade games will start to integrate with smartphones, but it's about time they level up.