As mentioned in a news group, business owners and IT personnel should be aware that:
MPLS VPN = "Stick a label before the still unencrypted IP packet".
MPLS doesn't secure your data, you are responsible for keeping it secure on the wire.
In light of recent revelations about government interception of data, businesses should be aware that data going across private circuits, is not secure. It can be intercepted and monitored if it is not encrypted at business owned and protected end-points.
Risks and costs need to be evaluated when sending unprotected data across third party physical and virtual links.
I have brought this to the attention of various clients and have offered ways of mitigating risks.
