Hey there. I actually grew up in Hawai'i, and ALL snakes- not just BPs, are illegal there. Most reptilian pets are, in fact- you can own geckos, anoles, and Jackson's chameleons, but that's about it. NO SNAKES, no skinks, iguanas, nothing like that, period.

The reason for this is because they have laws to protect the indigenous wildlife. Snakes would be predators to some of the local creatures- they actually imported mongoose to get rid of any snakes that managed to crop up. Of course, the mongoose ended up eating the eggs of the indigenous birds, and now they're pests as well... Hrg.

But yeah. The island never had any snakes on it to begin with(or ants or cockroaches, for that matter), which is why they're not allowed.