Read your owners manual or bring your car into the dealer to have this feature turned off. I'm pretty sure that it can be disabled.
You may want to drop into your dealer and ask if it could be reprogrammed. Most cars these days have body computers that could customise several features, and the door locking may be one of them. I find it highly unusual that, especially being in North America, your car would do that. "Illuminated Entry" is something that originated in North America precisely because of the nature of crime there. I wonder if Toyota isn't getting sued for endangering its occupant's safety by making them needlessly vulnerable.
Does your car have an aftermarket alarm? I remember reading brochures of car alarms where they can be programmed to also unlock the doors upon selecting Park.
Due to the fact that newer vehicles have Body Control Modules that control features around the body (self-explanatory), I would ask the dealership about this.
"I wonder if Toyota isn't getting sued for endangering its occupant's safety by making them needlessly vulnerable."
I wouldn't be surprised. They are being sued for LOTS of things these days, such as sticking accelerators and other major safety defects. Three Grand Jury subpoenas in one year for safety violations doesn't indicate a very well built car.
After 5 years with my 2005 Camry not behaving this way (only the driver's door unlocked), I am very happy that my 2011 Camry does unlock all of the doors. I keep my work bag in the back seat and it was a nuisance to have to go back to re-open the driver's door to unlock it manually. I understand the safety piece but in my area it's really irrelevant. I'm betting the consensus was to open all of the doors for convenience.
You should sue a car company because the doors don't automatically lock? Yeah, okay! Why don't you learn to do it yourself and create a habit out of it, so it becomes second nature to you, since it is so important to you?
There is probably a setting for it to do whatever you want anyway. Just ask the dealer about it.
I really love this feature of the Camry (all door opens when put in park). Great convenience for me. I understand the security issue for some, however it can be programmed to operate differently as mentioned.