Was there anything wrong, with the good old mechanical locks in train toilets? The only thing wrong was the fact that they weren't "modern" enough, i.e. too si

Was there anything wrong, with the good old mechanical locks in train toilets? The only thing wrong was the fact that they weren't "modern" enough, i.e. too simple and predictable. That said, you can easily "DoS" a mechanical lock too, if it doesn't have any form of interlock. Everyone who has locked themselves out of cars and buildings (e.g. leaving the key inside) will clearly remember this.