In reply to Lynsety:
There are a number of schemes, the one you have named.
The others are Bike Shepard
http://www.bikeshepherd.org/
and Immobilise which is used by some Police forces to access ALL stolen goods registered on that site not just bikes.
https://www.immobilise.com/
Not that it will get a bike back though, but may help.
My MTB was stolen having been on these databases and a rf frequency fitted (immobilise). It is still out there after 3 years.
The police in my area didn't even have a clue about the databases when I told them and they didn't have the tools to evaluate the rf code either.
I think it had the barcode tag on from kryptonite as well.
There is also datatag as well.
All depends on whether or not the bike is still in this country after being stolen or has been stripped for parts.
Select DNA can be used on some parts but again you're reliant on the police checking items over with a UV lamp to check if its there in the first place.