In my travels, I have happened to make the acquaintance of a professional locksmith. The why is immaterial, but let's say he gave me an education that afternoon. Here are his views on security:
1. There is no lock ever made that cannot be defeated with sufficient time and resources.
2. The purpose of a lock is not to secure something, but to delay a would-be thief. Time is the greatest enemy of the thief. Too much time spent trying to bypass a lock is what causes them to get caught.
3. There are three classes of thieves, opportunistic thieves, amateur thieves, and professional thieves.
4. Opportunistic thieves are generally stupid teenagers who seeing an unlocked bicycle or car with the keys left in the ignition will hop on and take off. These persons can be stopped by the most basic of security measures, ie, cable locks on a bike and auto door locks.
5. Amateur thieves are more savvy. They steal things for a reason, generally to sell. Ever seen "Gone in 60 seconds" - those are actually higher-end amateur thieves. They know how to bypass locks, hotwire a car, etc. Thankfully, they know enough about locks to know what ones they want to avoid, in other words, they know which locks they can pop open easily, and which ones will likely have them standing there for 10-20 minutes trying to get it open. In the latter case, the amateur thief will go looking for an easier target.
6. The best thing about professional thieves is there are very few professional thieves in the world, and those are usually not looking to steal one persons property because the average person doesn't own anything worth enough to be worth the risk of them getting caught. No, these guys go where the big money is. Corporations, governments and the like. They have more in common with James Bond than your average street thug. They are nearly impossible to protect against with any mechanical or electronic device. You need human guards to secure something against a professional.
With all that said, let's do a quick headcount. Most thieves can be stopped by a simple Master lock. Most amateurs can be stopped by a good Abus lock. Professionals aren't interested in what one person has except under the rarest of circumstances.
That said, a great lock on a crappy piece of Wal-Mart dog chain does not make something secure. A length of excellent Pewag chain with an Abus lock means nothing if you loop it around handrail that can be pulled loose with one good yank. Remember that the thief will look for and attack the weakest point. If you can delay them for 60 seconds... they will generally walk away and you win.
So, when my buddy Mike and I are going to Alaska next year, we're planning to chain our two bikes together in the parking lot. This makes them a lot more difficult to steal, and we'll be using Pewag chain with Abus locks. Opportunistic thieves will see a lock and chain and keep walking. Amateur thieves will see Abus and Pewag and keep walking, looking for an easier target. We don't expect to have any issues.
