On the contrary, it is easy to take out. They can do it in about two minutes. A crow bar and wire cutters is all it takes. This is why removable stereos are preferred. It is just a sign of the times. I had mine ripped out like that, and I had to replace my entire console and convertible top. They went under my hood, cut my battery cables to disable my alarm and then cut through the back of my folding convertible top. Plus, the thief left 22 caliber bullets and a Crack pipe in my back seat which he obviously lost while committing the crime. And, I lived in a gated suburban community.
I had a work colleague with a removable stereo, and he took it out and placed it under his front seat. Thieves watched him and realized that he didn't take the stereo with him when he left his car. So, they broke into his car, found and stole it.
There was a time that I had a shotgun during my stereo theft. But, would it have been worth it to kill some desperate drug addict over a $300 stereo, when he is already dying a slow horrible death? In all justice, I prefer the thief to die that way, instead of me becoming a party to his death. Take my stereo and die in your own misery. Sadly, this is how I feel.