Edited by Martin G on April 7, 2018, 1:03 pm
Much easier than pounding the streets looking for the right model of vehicle, from the right year, in the right colour.
"Yeah mate, I can't find the log book but you can check it out with the DVLA's website; it's all kosher."
And sure enough, the reg number checks out as a red 2003 Triumph Thruxton, MOT'd, taxed and insured.
Less of an issue with rarer classics, more of a problem with modern bikes which might be stolen and then sold on with a fake identity.
Edit to add: And it's the ability to search for a specific vehicle online that makes it more of a risk than just parking up at a bike meet, say.