My wife's bike was stolen about 200 yards from there a long time ago (they kicked our front door in and stole it from there plus an electric razor and half a bottle of aftershave – yep, I have no idea either). I found it the next day chained to a bench in the shopping centre (the bike, not the aftershave), shot home, pocketed a pair of flails and then went and sat in the shopping centre for 4 hours watching the bike. I was *very* angry.
My wife came along and talked me out of killing the people who would come for it. So I borrowed some bolt cutters and took the bike back. No-one stopped me or asked what I was doing while I was cutting the chain.
Sorry, this doesn't help. I'm almost certainly too far away now to come across this bike but I'll keep my eyes open.