Re: MAC filtering, all that does is create trouble for legit users.
"The idea is not that your lock will be inviolable but that faced with a rank of bikes a thief is going to go for the easiest locks first."
Yes but like thieves, the intentions/ambitions of the thieves may vary. Faced with a row of bikes, some thieves may ignore them and go for a nearby Mercedes. More effort may be required but reward vs effort vs risk calculation is different. Some hackers may see increased security as a challenge and imagine the promise of something more worthwhile than access to someone's willy photos.