Yes, mine broke last summer. You're quite right it's a safety issue so the first thing you need to do is file a report with NHTSA.
The problem is a small plastic two part spring loaded push rod that connects the release trigger on the shifter lever to the mechanism below. The plastic is fragile and breaks resulting in the symptoms you see. The picture shows the upper half of the rod. The small plastic nib on the RHS has broken off the end of the rod. This nib mates with the lower part of the rod, still inside the shifter, and holds the spring under tension. When the nib breaks off, the spring is free to push down and has the same effect as pushing the release button on the shifter lever thus allowing you to freely move it throughout it's entire range without needing to press the trigger.

Of course you cannot buy this 50c part so you either have to improvise your own fix or drop $$$ on the entire shifter mechanism.
Here is my solution machined from brass so it should last the life of the vehicle
The parts

...and assembled

Of course, you could replace with a solid rod. Maybe a chopstick cut to the correct length and do away with the spring altogether. The spring simply allows the rod to "give" if you push the release button on the shifter lever while it is in park and the brake is not applied and thus prevents you from being able to apply too much force to the brake interlock solenoid.
BTW, If you disconnect the interlock cable from the shifter end you will be able to remove the key.