I could lift a Vespa up on my own and put it in the back of a van if I wanted. Chain it to something; lampost, grid, drain, maybe invest in a ground anchor. Put a cover on it, and make it a tatty cover. Lock the cover to the bike also. Essentially have just a bit more security than the next one, then they nick his instead of yours. You're right to query the sold secure etc ratings by the way