Ridiculous! There are many more pressing issues on the island, but this one is certainly "easier" (for the PD) than dealing with preventing crime and stopping drug dealing and prostitution, so it doesn't surprise me at all that this happened.
A few questions immediately came to my mind if and when they do start enforcing these new rules:
1. How to prove ownership of your bike if you bought it used and don't have a receipt? We shipped ours from the US after purchasing on craigslist and have digital photos of them we took before we even shipped them, but we don't have a receipt. I suspect most locals are going to have a hard time documenting "ownership" since they didn't know they needed to keep their receipt for years, if they ever got one. Many, if not most, bikes are bought used from an individual and receipts just don't change hands.
2. If you aren't riding at night, why should you be stopped for not having a light? We have headlamps for riding at night (and mine has bright red blinky in the back), but I don't plan to equip my bike with lights for the very few times we ride at night. They'd get stolen, I'm afraid. I doubt I can even buy them on the island.
3. Helmets? I always wore one in the US and think they're a good idea on the road, but I don't wear or have one here. Are they even available for purchase here on the island? It's hard enough getting motorcyclists to wear 'em, if the folks I see riding north of the bridge (many sans helmets or with the straps not even buckled) are any indication.
It will be interesting to see how all this develops...