It is unfortunate that this post even needs to be written but it does. Many brokers don't inform their clients enough about security because they don't want to scare their clients out of listing and selling their home. That is a problem as far as I am concerned. Our duty to you is to inform you about the good and the bad. There are always security risks when you are selling your home.
Let's start with the folks that have security systems. If you have a security system (something I recommend to everyone) make sure it is working, including the surveillance system. Next, add a new code that you will give to your listing broker, never use the primary code. You can also change the code from time to time just be sure to let your broker know. Be sure to delete all codes completely if your listing is expired or you withdraw it.
Next we move onto open houses. I have a dirty little secret for about open houses, they don't sell houses! Well they do but a very small percentage. Under 5% and probably close to 1% of homes sell from an open house. Open houses were an ingenious invention cooked up by real estate brokers to make contacts with potential buyers. The problem I have with open houses is that it is almost impossible for a broker to keep an eye on multiple people roaming through your home. They may not even be able to register everybody if it gets too busy. It is a great opportunity for someone to case your joint. If you do decide that you have to have an open house please take all the precautions you can.
One of the big problems I have with people that do FSBO's is the fact that they have no control over security and no way to vet potential buyers. This is only one of downfalls of selling your own home but to me it is pretty huge. When you use a broker, they work with other brokers through the showing services or through their office. They make darn sure that before they give out the lockbox code they are giving it out to a licensed agent that has had a thorough background check and has a great deal to lose if their license is yanked. The broker working with the buyer also knows the buyer (at least a little) and has contact information and knows what the buyer looks like.
If you want to safeguard your home there are a few basic steps to take. Believe it or not the number one thing taken from homes during showings and open houses is prescription drugs. You also need to hide or lockup your jewelry and don't leave any keys laying around. You may even want to take down and store any nice artwork or something that would make someone come back later to take. You also may want to remove valuables from view when the photographer comes to take pictures and do a virtual tour. Nothing like a thief being able to case your home from the comfort of their own home.
No lockbox is 100% secure. If you notice your broker's lockbox is missing or has been tampered with, call them immediately to investigate. You may need to change your locks if this happen.
Just a few small steps and understanding human nature will make your selling of your home much safer.