Judging by the sticker on the dowtube, it looks like the bike was on one of the bike registers. That would suggest it's more than a clunker to the owner. Sorry, cutting the frame is too far. As described earlier, contacting the police and then cutting the lock would be OK in my book, but I think you've just written off someone's bike. Imagine how you would feel the other way round.
thanks for your input; who would do the cutting in a public place, police or me? i've tried cutting the lock initially, but it wasn't working with the tool i had. their bike can be repaired if they want to. i'd feel fine, had three bikes stolen in london over the years, no negative emotions. i'd feel different if one of my "nice" bikes was stolen, but i try not to leave them unattended.
Exactly.
As pointed out above from the LFGSS thread, bitch-locking a bike is considered as a form of criminal damage as it deprives the owner of access to their property. Whilst this doesn't automatically mean that the bike in question is fair game there needs to be a consideration of how much time and money one is willing to expend to get their bike back, money that will almost certainly not be recoverable.
Consider the extremes...
A solution costing £0, not affecting the other bike, and taking barely any time at all would obviously be ideal. But this wasn't available.
zigzag tried the other £0 route of waiting 24+ hours, leaving notes, etc, but that didn't work.
Having to spend £500 (inflated figure used on purpose) to short notice buy or rent a large set of bolt croppers or portable angle grinder would, hopefully, get your bike back and leave the other bike unaffected (if you dropped it in at the local police station for example). But that's a lot of money, plus the hassle of renting and returning the items, etc.
Given those two extremes the reality of the various options will be somewhere in the middle, and everyone will have a different opinion of the amount they are willing to spend (and time they are willing to wait).
If it was, say, £50 to grind off the lock (and leave the other bike undamaged) and a few hours extra hassle of renting/returning the grinder, but £3 for a junior hacksaw from a nearby hardware shop to cut through the seat stays in 5 minutes then, depending on lots of other circumstances, the latter might seem like the preferred option at that time.
It also comes down to how urgent the need for the bike is. If this was my cheap commuting hackbike that cost me £20 I'd be willing to sit it out with a note on the other bike for much longer than if it was an £2000 bike I needed for an Audax or other ride a day or so later (especially if this could be a targeted theft attempt).
Finally, in this case, the cost of repairing the seatstays is proabably about the same as the cost of the D-lock that would have been cut off. It's just getting the seatstays fixed isn't an item you can order online or buy quite easily on the high street. (EDIT - they're also down the cost of the D-lock too, so this equivalence doesn't quite work here.)
