Like Douglas Short, I'm familiar with the U.S. scene.
When I first moved to Canada in 2005, I was very surprised how the system works here. Rarely any verification (like date check, preferred411 or just individual references) is required. It's similar to what I've experienced in the UK (England in particular), where the adult industry is of lesser concern to the criminal justice system and law enforcement. Accordingly, there's less worry about police stings and guarding against that.
On the other hand, due to the anti-prostitution zeal the law tends to take on in the U.S., escorts in that country have to take greater precautions that the appointments they are making are not going to turn into police stings (e.g., the verification system). In this way, escorts are afforded a greater sense of security when using the verification system (while clients might feel that their own privacy is compromised). But, that's just the way it works and I've never found my personal details used against me.
You always have to remember that without formal verification, escorts are always taking a risk (e.g. based on a phone number alone), and vice versa. But, here in Canada, it seems to be a system that works more in the favour of clients, fortunately or unfortunately.