If the public knows what an owner has in a collection and is easily identified what else might a person own?
Think about that for a moment.
General forums are slightly different from other more controlled websites.
This goes hand in hand with your location, so I frontloaded this point first versus location alone.

No one should show an accurate location on a map of where they live, just general town center point, if they are inclined. Otherwise, this invites issues against personal safety and at minimum invasion of privacy.

Other reasons are presumption of pride regarding the "look at me" factor which old collectors prefer not to participate. This wears off over time. This generates illogical envy for some. This is especially true when a person owns very rare, desirable, and expensive game titles, prototypes, or even artwork. Inquiries and "offers" are frequent, and often unwelcome.

Others provide no information out of desire to conduct trolling behavior and keyboard courage. I was privately threatened by pintards on this website, along of accusations and attacks of identity, knowledge, and experience. Highly negative, childish behavior.

Established collectors most likely know a specific individual probably already know who they are, what they collect, and how to reach them privately, if required for support or assistance.

Rolling codes are ineffective against average intelligence thieves. Contrary to what may be believed, an a basic frequency switching modular garage door opener can be made to bypass this type of security using parts found on Amazon for only a few dollars and a basic understanding of electronics. The only method of avoidance of electronic frequency "picking" is unplugging the motor assembly, but that will not deter a real thief.

Sliding deadbolts on on a garage doors do not work either as they can be bent upwards using a crowbar on the sides of the garage door. Zip ties on the rails are a complete joke. Locking the garage is useless, as the lock from the lever can be cored out in 5 seconds and a set of pliers used to turn the fulcrum point, or the lever itself is removed and bypassed. Using the same crowbar with leverage, a person can lift the garage door up far enough to get a hydraulic car or scissor jack in place to allow more than enough room to crawl and roll under the door. Many times people do not dead bolt or lock their inside house access garage doors going into their home out of laziness. By far the easiest "test" access to a home (to verify alarm while still being able to steal), and not even generally alarmed for basic homes without collectible automobiles. If the thief stays inside the garage, they have a "safe zone" to do whatever they want, for as long as they want, and no one will see them.

The only way to prevent a garage door from being opened permanently is to install two very heavy boat chains with clevis and hooks through the rails at bottom and middle of the door and wedging the rollers at the top. The chains are locked with 1000 series locks with no exposable hasp. Then the only way it can be opened is by ripping the entire door off the hinges with a chain hook, truck, and tow bar hitch.

Those that believe thieves do not troll forums for targets such as guns, coins, guitars, pinball, gems, stamps, baseball cards, or whatever choice of collectibles are completely fooling themselves.

Protect your property.
Add a security system, if necessary.
Add security signs, even if you do not have a system.
Add sensor lights around your home as a minimum precaution.
Think like the thieves, that is what professionals security services do.

The intent of my experience is to share one simple way of how to deter thieves regarding removal of pinball machines from easily accessed locations (ie including advertising the direct physical location of your home on a public map and what you own), not prevent the entire spectrum access into a private home and stealing collectibles.

If a person has extreme amount of small valuables, lock them up in a full size safe, hide them in walls, own a guard dog and keep it indoors, or hire a security guard by living in a gated community. Better yet, use a safety deposit box at a bank, it is cheaper, unless you have a firearm collection.

If a person lives in small apartment, or decides to directly sleep under pinball machines, some of these tips may not apply to you.

The present carefree attitude towards social media prevalent today is particularly dangerous, and if person is reasonably smart, they can figure out just about anything via backtracking information and/or including use of darknet websites such as where you live, but you can still deter the theft itself, which is my point, not to attract zombie apocalypse theories. I am not referring to identity theft either, which is much more common. Many times I have heard the statement, "I did not know."
Now people know, if they choose to continue to learn.
If people choose to ignore, things do happen.

Pinball machine theft has been on the rise since 2011, again, mostly from businesses, because the sales market has been strong.
If this information is doubted, conduct the some quick research.

Knowledge is power.

It is not like people (or myself) are advocating bear traps, landmines, and shotgun tripwires for protection.
In the United States, it is illegal to install metal bars and grates in some private homes (including storage buildings and garages) due to fire codes, including businesses in some states. Abroad this is totally acceptable along with things like razor wire and electric fence along private homes, not the outer property walls. I would love to do some of the latter things in the USA, as it definitely makes a serious difference, to which I can personally attest.

Thieves don't like to maneuver pinball machines through tight hallways and certainly not through regular size windows, but have no problems busting through bay window style doors with a crowbar and blanket. This last part was a good example, because I tackled a thief who did this action to my direct neighbors house and restrained him when I lived in Texas. Firearms are not always a good idea, if you are not personally in danger and in this case it was not my property.
Thieves have no preference to carry machines up or down stairs either, and they do not often bring the right equipment.
Thieves don't carry games out onto roofs and lower them down on pulleys and ropes with a crane or gin pole.

The "boat chain method" to which I have used for nearly 30 years (since renting and owning multiple houses) prevents easy removal of machines from a garage or equivalent building. The access point is effectively blocked, time consuming to remove for a thief as it is yet another puzzle they must solve, and increasing the chance they may get caught, heard, or observed. The chain tension prevents movement through the center of the door when pinched through both chains. The chain is thick enough that even common small size bolt cutters are ineffective. Sawing takes time. A plasma torch does do the trick, but they have to unhook the whole contraption. If a thief tries to entire into the home and back into the garage, they already tripped an alarm. It is a whole lot more effective than even installing an alarm sensor in the garage, and does not cost that much to install yourself, and even can be reused as needed in the future if you decide to move.

It is not that difficult for a person to pull up with a storage truck, pop a lock on a garage (or a storage location), and load games.
It does happen, although infrequently, but why take the chance?
If a thief enters your garage and sees pinball machines there for example, they will be even more inclined to go into your home.
Operators don't advertise their warehouse locations for the same reasons and are usually gated.
Garages are by nature on first floors, separate buildings, or sub basements and called "easy access" for a reason.
Some homes even have private loading ramps on sub doors along the sides or front, especially those people that own coin operated equipment.

If enthusiasts are unsure pinball machines are stolen directly from homes including my previous points and concerns including garages and upgrading security methods.

Note: Some thieves have the intelligence of squirrels, both literally and figuratively.

Three years ago in my own city.

This is not rare, pinball machines secondary values are lucrative for some just like cars, even if thieves do not know the difference on titles and actual worth.

http://www.kptv.com/story/25314531/determi