Just my penenth on this and cover a few points raised, I have personally refused a meter upgrade by my supplier on 2 occasions mainly due to them wanting to install a generation 1 meter which in many cases is not compatible with other suppliers if I decide to change supplier, this could see me with additional costs to swap supplier.
The smart meter logging of power outage has been and does get used as evidence of tampering, I know because I had a friend who got caught up in this, he had a new meter fitted when he moved into the house and a year later he rang them because he wanted to change his consumer unit and the electrician needed an engineer to come out and do the change over to the new board... their quote was extortionate for what what a 15min job (About £350) so he went down the path of getting it done himself, it would seem this request had put him on a watchmode and when the meter was powered down it logged time, date and duration, as this didn't tally with any network power problems then the cause of the power down was investigated, subsequently he found himself in court as he would not disclose who withdrew the cutout fuse, in the past the energy companies have had difficulties going to prosecution as it was never easy to prove when a meter lost power.
I am not surprised at all if there is a cutout option in smart meters as this would be of a great advantage, when the supplier wants to stop power been used at the moment it is a costly method of sometimes having to gain forced entry, utilising the police service etc etc and the following legal costs in doing so, if you can simply send a signal to shut down it would take seconds to do. There is also the other advantages like network faults, if you tell the meters to lock out in power down this is of a great advantage to network engineers when the local grid is energised again, it limits existing load when energising and thus helps prevent mains transients that can damage equipment, I wouldn't be surprised if following a power up that a area could effectively be signaled to energise each property with a smart meter in steps as oppose to all at once.