Similar, but not the same...

*You* look at what I wrote about the security guard - there's nothing live going on.  Nobody is collecting data on his wheereabouts when he goes round, the Deister machine is not transmitting to anyone, just storing it for audit purposes or dispute purposes.  It was merely an illustration that the hardware exists in a simple enough form to collect and store the data that's all.  If it's got a "nuclear key" where both parties have to provide some security information to even get into it there's no problem.

But then I suspect people who do not want any form of road pricing will find something wrong with every technological suggestion.