Like everything else, there is no way to absolutely prevent the theft of your bonsai. No matter what methods or devices or locks you use, a determined adversary still has a reasonable chance of successfully stealing your valuable trees. So let's consider some reasonable things you can do to make stealing less likely and more difficult for the "bad guys", keeping in mind that we love our bonsai and want to show them in attractive surroundings easy to view. We can however, take a few measures to decrease the likelihood of theft.
To consider how to prevent stealing we should consider the reason or category of stealing.
Here are a few various categories of thieves:
Those who steal:
1. On impulse
2. For personal collection
3. For profit
4. For others
5. "Street Sign" thieves (trinkets for their room)
6. For revenge
Category #1 is unpredictable and may be the easiest to prevent. They strike when attractive items are visible-known as objects of opportunity. A reasonable amount of visual screening will prevent this as they strike on impulse attacking spontaneously with no predetermined reason to do so. Probably these people have little or no idea of how to keep a bonsai alive.
Category #2 is the despicable person who, probably knows what he is doing, wants a bonsai without either paying for it or taking the time and energy to make one. In most cases this person would have reasonable knowledge to take care of the bonsai, at least until major work is required. Very difficult to protect against since they know where the bonsai are, they may be somewhat ineffective being amateur thieves.
Category #3 could have various causes. With the increasing use of drugs, this becomes a serious area of concern. Less likely to know what he is doing, and since the bonsai community is fairly knowledgeable about who has what, selling them is difficult at best. Brokers probably know they cannot keep them alive, and likely don't know buyers. Having stolen a bonsai one has to get rid of it fast or it will die. (I hate to say it, but this is the best deterrent to theft-a quick death so they don't go to all that work again.) Unfortunately, drug users would be happy to get $50 for a $5,000 bonsai.
Category #4 it is scary to think about people with money who want one, but don't want to pay for it, so they engage a professional thief to get it for them. It is almost impossible to guard against this highly sophisticated category.
Category #5 typically teenagers, who as a hoot or on a dare, elect to acquire various and diverse items to decorate their bedroom or dormitory. This is unique because they have no idea how to take care of them, have no empathy with the owner, and are absolutely unpredictable
Category #6 was thrown in since it is possible. Hell isn't hot enough for the person who would do this, but there are all kinds. Not easy to defend against and even less likely recovery.
Various devices and technology have been tried with mixed results. Fortunately, the theft of bonsai has not reached epidemic proportions; correspondingly, and because this has not yet occurred, there is little experience in security and recovery of stolen bonsai trees. Below is a list of possible security devices.
Cable and lock tie downs
Release switch under bonsai
A word on each:
Security Guards: Extremely expensive and only reasonable for large public collections. Even so, unless they are on duty 24-7, the thief will strike with impunity when they are absent.
Guard dogs: Curiously more effective for a private collection that a public one. Having a dog that will bark at intruders will wake you and scare the thief. This depends on someone being at the site to respond and the dog not only getting to the thief but also being immune to pacification with a sirloin steak.
Locked fences: Probably effective for impulse, poorly motivated "street sign" thieves, or revenge. If the fences are opaque barriers hiding the bonsai from casual passers-by it will go a long way to thwart these categories.
Cable and locked tie downs: Probably good for all categories except the "for other" category where professionals come prepared and cut same in an instant with bolt cutters.
Release switch under bonsai: As good as a guard dog if you are home providing they are tied to a secure alarm system. However, most devices fail due to the extreme environment, especially the water. Of course you don't have to house, clean and feed them, etc.
Remote sensors: Electronic methods to detect the presence of unwanted "guests." Problem with electronic beams or motion sensors from animals and birds setting them off-causing one to turn them off. Electronic chips placed in the tree or pot is good to prove ownership. Passive nature of these devices requires using a "reader" very close to the trunk to detect the response to a given signal. Sophisticated active devices like the auto "Lo Jack" which sends a signal to a satellite for immediate location anywhere are exceeding expensive just short of having live security guards. They are expensive to buy, need power to "drive" them, and require a monthly charge for the service. Nothing, not even 24-7 guards, works better at locating a stolen bonsai. If your bonsai are sufficiently valuable, you have been hit often, and would thoroughly enjoy nailing the culprit bad enough-this is the way to go.
Trip wire: A reasonable way to know someone is where they should not be. Clumsy and not as tidy as the electronic method, this device is subject to violations from all manner of meaningless intrusions.
Cameras/video: Over rated, requiring too many, a lot of light, recording devices, and constant checking to know if an event has taken place. Also expensive requiring considerable equipment. Must be highly visible to be a deterrent, hidden to avoid being overridden, or masked.
Alarms: A supplement to any and all of the above. Effective if extremely loud to annoy the thief and hopefully cause them to abort the effort. This can have the same effect on the owner tending to have them turn it off at the wrong time.
Lights: Like the alarms can cause the thief to abort, it is needed for decent camera/video effectiveness. It is well known that a very well lighted area can deter thieves. Having it on all night it may destroy your bonsai preventing you from using it in the most effective manner, not to mention keeping you and the neighbors awake all nights.
It is very hard to keep your bonsai a secret. People learn what you do, and not without a little bragging and showing off. If you have really good bonsai it is likely you are qualified and called upon to teach. Any class can contain people of each of the above categories noted above. Officers of clubs, persons placing their bonsai in club shows for the public, newspaper articles, and so on increase the visibility of who has bonsai..
Enjoy your bonsai
Block the view from the "street"
Present bonsai to the public
Let people know there is a lot to it
Display in exhibits and shows
Encourage people to try
Have gated access
Have someone watch when away
Keep up-to-date with the SBR
Keep current photos of your bonsai
Brag so much
Display for public view where you keep them
Don't make high value an issue
Don't advertise extreme values
Don't hand out your address
Stop telling them it is so easy/no work/anyone can
Don't leave the gate open
Don't advertise your gone (newspaper, mail in driveway)
Don't let the Registery waste away becoming impotent
Let people know:
Without daily care by knowledgeable people they die fast.
It has intrinsically value only to you-the creator.
You could never sell for what it is worth to you-to anyone.
There is no street value for any bonsai.
Loss of even one limb could render it trash.
There is a Stolen Bonsai Registry, bonsai are easily recognized.
Check the Registry once a week or so to keep familiar with what is out there floating around. If you see one report it.