What Santa Cruz PD is doing is great...but....
As the article states, there is no statewide database or bike registry run by the State of California. DMV does issue "Bicycle License" stickers and keeps track of which law enforcement agency has been assigned which numbers when they order a bunch of the stickers.
Problem is, most law enforcement agencies in California do not have a local licensing program that utilize these stickers. No time, money, or personnel to keep up with issuance and recordkeeping. So most don't order them. Also, some may have a program one day and the next it is gone due to budget cuts or inactivity (a department I worked for had very little interest from the citizens of the municipality as far as bike licensing). I remember an instance where I was dealing with a recovered bike that had a license sticker, got the info from a CLETS check with dispatch on what department "owned" the sticker number, contacted them and was told they no longer had a program of local licensing and they no longer had the records...someone decided that after about 8 years of inactivity there was no reason to keep the index cards the owner info was stored on.
The stickers can also be removed...takes a bit, but they do come off and many dirtbags who steal bikes remove or make illegible the stickers...they just scratch as much of them off as they can.
The non-law enforcement or commercial "Bike Registries" are next to useless as well, as most cops/dispatchers wont bother or do not have the time to try and check some website or call a phone number when a bike is recovered with one of the stickers from those organizations. For law enforcement, it is ALL about the serial number and any state issued ID number they can run easily and quickly through the statewide database...this is their preferred method and the fastest (and what would be done, I am sure, by Santa Cruz PD before they even bother to run a bike license number). The below is from a post I made on MTBR previously....it covers what really happens when law enforcement recovers a bike and what every bike owner should do to ensure they can get their bike back in case it gets stolen:
Most cops, when dealing with a potential stolen bike, will have their dispatcher run any serial number found through the law enforcement data system, not any of those consumer online registry services or any other registration scheme. Most states have their own database/computer system (i.e. in California - C.L.E.T.S = California Law Enforcement Telecommunications System) which will store the bicycle make, model, and serial number if that info is given to an officer when they take/write a crime report for the theft of that bicycle. If you report your bike stolen but do not have the identification info then you are S.O.L. - there is nothing to enter into the law enforcement data system that will get your bike back to you: they cannot enter partial info, such as "a black Specialized mountain bike"....you know how many of those get reported? They cannot enter a record without a serial number and make/brand.
Some states even push their data records into the national crime data index (NCIC) so if your bike is stolen and you report the serial number and it is recovered out of state you still may have a chance to get it back.
One of the best things to do is take a photographic record of the bike, with good lighting and clear shots, that show the whole bike from both sides, the front (showing brand headbadge), a close-up shot of the serial number (bottom bracket is usual location, sometimes on tubes or rear dropouts), and shots of any particular parts/components/accessories you may have upgraded that are different than stock. Keep printed copies of these photos along with a complete identifying description (including Serial Number!) and replacement costs (bike and upgrades/accessories) that you can hand over to a law enforcement officer when they come to take a report of your stolen bike. Update your photos/id info when you make changes to your bike.
Another thing to think about that helps law enforcement get your bike back to you is adding YOUR identifier to the bike frame. Take an engraver and engrave your driver license number somewhere on the bike frame. Since that number is something your local law enforcement officers are constantly running through their computer system it will stand out like flaming letters to them. It will quickly and easily give them access to your name and address, being one of the best methods of getting your bike back to you even if you do not file a stolen report to get the serial number into the crime database.
Another thing to think about is putting your contact info in to the frame, via the seat tube or bottom bracket. When I was managing the property/evidence unit for a suburban California police department I would habitually look for any type of identifying info on the bikes we would get in as recovered or found/abandoned. I would remove the seat/seatpost to see if anything was in that tube, and since I was a bike mechanic I would also remove the cranks/bottom bracket. I got bikes back to some people because they left slips of paper inside the frame with their contact info on it (and charged some bad guys with theft or possession of stolen property...depending on how the bike came into the department's possession) or due to a bike shop putting their business card in the frame. Some bike shops would put their card in the bottom bracket or seat tube back in the day...I have called up shops who found customer info in their records with which I used to get the bike back to the owner.