I didn't have a ground anchor fitted so the bike was just chained to the "security" cover at the front and rear wheels, the front via a D-clamp,the rear via the chain.
The front and rear wheels couldn't have turned due to the locks so the beggers must have lifted the bike up with the cover on and carried it off, I'm guessing into a van. The back gates are ply-board and were barricaded shut so they must have been watching me come and go, then waited till we were in bed, climbed over the back wall (which is 8ft high!) and then opened up the back gates from the inside, then lifted the bike out.
I've bought some pad lockable shed door type locks with alarms on them for the rear and side gates so that now as soon as anyone tries to tamper with the locks, they go make some noise.
I've now fitted a ground anchor and bought an Oxford screamer disk-loc alarm so, as long as someone's in the house, anyone meddling will be alerted. I've also bought some security cameras and plan on building a brick shed to keep my next bike purchase in.