Just read on another local bikers page, after coming home from a day ride with friends, guy cleans bike immediately, then finds tracker attached to bike, scum nicking bikes to order, fitting tracker at some cafe, as to be able to follow the bike home and then it gets nicked, be aware!
Is this that old SRAD looking shed? More likely fitted by previous owner and just found... Although classic car enthusiasts are reporting similar stories on FB
As above I've heard of a bunch of dirtbike people around Surrey finding these. They are cheapo chinese trackers and the batteries run out pretty quick apparently but it's enough to lead to your house and loads of people have had dirtbikes nicked over the last year or two.